{"id":30,"date":"2022-04-13T06:09:21","date_gmt":"2022-04-13T06:09:21","guid":{"rendered":"http:\/\/9thclass.deltapublications.in\/?page_id=30"},"modified":"2025-11-20T06:56:06","modified_gmt":"2025-11-20T06:56:06","slug":"b-3-evaluate-variable-expressions-involving-integers","status":"publish","type":"page","link":"https:\/\/9thclass.deltapublications.in\/index.php\/b-3-evaluate-variable-expressions-involving-integers\/","title":{"rendered":"B.3 Evaluate variable expressions involving integers"},"content":{"rendered":"\n<div class=\"wp-block-group has-normal-font-size\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h2 class=\"wp-block-heading has-text-align-center has-text-color\" style=\"color:#00056d;text-transform:uppercase\"><strong>Evaluate variable expressions involving integers<\/strong><\/h2>\n\n\n\n<p class=\"has-text-color has-huge-font-size\" style=\"color:#74008b\">key notes :<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>Understanding Variable Expressions<\/strong><\/h4>\n\n\n\n<figure class=\"wp-block-table has-normal-font-size\"><table class=\"has-text-color has-link-color has-fixed-layout\" style=\"color:#000060\"><tbody><tr><td><strong>Definition:<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"has-normal-font-size\">A variable expression (or algebraic expression) is a mathematical phrase that includes numbers, variables (letters representing unknown values), and operations.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table has-normal-font-size\"><table class=\"has-text-color has-link-color has-fixed-layout\" style=\"color:#000060\"><tbody><tr><td><strong>Variables:<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ul class=\"wp-block-list has-normal-font-size\">\n<li>Variables are symbols (usually letters) that stand for unknown or changeable values.<\/li>\n\n\n\n<li>Example: In the expression 3x+4, x is the variable.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table has-normal-font-size\"><table class=\"has-text-color has-link-color has-fixed-layout\" style=\"color:#000060\"><tbody><tr><td><strong>Evaluating Variable Expressions<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<figure class=\"wp-block-table has-normal-font-size\"><table class=\"has-text-color has-link-color has-fixed-layout\" style=\"color:#000060\"><tbody><tr><td><strong>Substitution:<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"has-normal-font-size\">To evaluate a variable expression, substitute the given value(s) of the variable(s) into the expression and perform the arithmetic operations.<\/p>\n\n\n\n<p class=\"has-normal-font-size\">Example: Evaluate 3x+4 for x=2.<\/p>\n\n\n\n<ul class=\"wp-block-list has-normal-font-size\">\n<li>Substitute x=: 3(2)+4<\/li>\n\n\n\n<li>Perform the operations: 6+4=10<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table has-normal-font-size\"><table class=\"has-text-color has-link-color has-fixed-layout\" style=\"color:#000060\"><tbody><tr><td><strong><strong>Order of Operations (PEMDAS):<\/strong><\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"has-normal-font-size\">When evaluating expressions, always follow the order of operations:<\/p>\n\n\n\n<ul class=\"wp-block-list has-normal-font-size\">\n<li><strong>P<\/strong>arentheses<\/li>\n\n\n\n<li><strong>E<\/strong>xponents (not typically covered in 6th grade, but good to be aware)<\/li>\n\n\n\n<li><strong>M<\/strong>ultiplication and <strong>D<\/strong>ivision (from left to right)<\/li>\n\n\n\n<li><strong>A<\/strong>ddition and <strong>S<\/strong>ubtraction (from left to right)<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table has-normal-font-size\"><table class=\"has-text-color has-link-color has-fixed-layout\" style=\"color:#000060\"><tbody><tr><td><strong>Steps to Evaluate Variable Expressions<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"has-normal-font-size\"><strong>Step 1: Substitute the Values:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list has-normal-font-size\">\n<li>Replace the variables in the expression with their given values.<\/li>\n\n\n\n<li>Example: For x=3, y=4, evaluate 2x+3y.<\/li>\n\n\n\n<li>Substitute: 2(3)+3(4)<\/li>\n<\/ul>\n\n\n\n<p class=\"has-normal-font-size\"><strong>Step 2: Follow the Order of Operations:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list has-normal-font-size\">\n<li>Perform any calculations inside parentheses first.<\/li>\n\n\n\n<li>Then, perform multiplication and division from left to right.<\/li>\n\n\n\n<li>Finally, perform addition and subtraction from left to right.<\/li>\n\n\n\n<li>Example: 2(3)+3(4)<\/li>\n\n\n\n<li>Multiply: 6+12<\/li>\n\n\n\n<li>Add: 18<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table has-normal-font-size\"><table class=\"has-text-color has-link-color has-fixed-layout\" style=\"color:#000060\"><tbody><tr><td><strong>Examples<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"has-normal-font-size\"><strong>Single Variable:<\/strong><\/p>\n\n\n\n<p class=\"has-normal-font-size\">Evaluate 5x\u22127 for x=2<\/p>\n\n\n\n<ul class=\"wp-block-list has-normal-font-size\">\n<li>Substitute: 5(2)\u22127)<\/li>\n\n\n\n<li>Calculate: 10\u22127=3<\/li>\n<\/ul>\n\n\n\n<p class=\"has-normal-font-size\"><strong>Multiple Variables:<\/strong><\/p>\n\n\n\n<p class=\"has-normal-font-size\">Evaluate 3x+4y  for x=1 and y=2<\/p>\n\n\n\n<ul class=\"wp-block-list has-normal-font-size\">\n<li>Substitute: 3(1)+4(2)<\/li>\n\n\n\n<li>Calculate: 3+8=11<\/li>\n<\/ul>\n\n\n\n<p class=\"has-normal-font-size\"><strong>With Parentheses:<\/strong><\/p>\n\n\n\n<p>Evaluate 2(x+y) for x=3 and y=5<\/p>\n\n\n\n<ul class=\"wp-block-list has-normal-font-size\">\n<li>Substitute: 2(3+5)<\/li>\n\n\n\n<li>Calculate inside parentheses: 2(8)=16<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-table has-normal-font-size\"><table class=\"has-text-color has-link-color has-fixed-layout\" style=\"color:#000060\"><tbody><tr><td><strong>Tips for Students<\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"has-normal-font-size\"><strong>Substitute Carefully:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"has-normal-font-size\">Ensure you replace each variable with the correct value.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-normal-font-size\"><strong>Follow Order of Operations:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Always use PEMDAS to avoid mistakes.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-normal-font-size\"><strong>Show Your Work:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Write each step to make your calculations clear and to check for errors.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-normal-font-size\"><strong>Practice Regularly:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Consistent practice with different types of expressions helps solidify understanding.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-text-align-center has-text-color has-normal-font-size\" style=\"color:#105000\"><strong>Learn with an example<\/strong><\/p>\n\n\n\n<div class=\"wp-block-group has-background has-normal-font-size\" style=\"background-color:#d3cefb\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group has-background-background-color has-background\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<p class=\"has-text-color\" style=\"color:#b00012\"><strong>\ud83d\uddfc Evaluate the expression for&nbsp;<em>y<\/em>&nbsp;= 2.<\/strong><\/p>\n\n\n\n<p>8<em>y<\/em>&nbsp;=&nbsp;<\/p>\n<\/div><\/div>\n\n\n\n<p>Plug in&nbsp;<em>y<\/em>&nbsp;= 2 and simplify.<\/p>\n\n\n\n<p>8y<\/p>\n\n\n\n<p>&nbsp;&nbsp;8(<strong>2<\/strong>)          <em>Plug in&nbsp;y&nbsp;= 2<\/em><\/p>\n\n\n\n<p>&nbsp;&nbsp;16            <em>Multiply<\/em><\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group has-background has-normal-font-size\" style=\"background-color:#e2fbbb\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group has-background-background-color has-background\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<p class=\"has-text-color\" style=\"color:#b00012\"><strong>\ud83d\uddfc Evaluate the expression for&nbsp;<em>v<\/em>&nbsp;=&nbsp;<sup>\u2013<\/sup>5.<\/strong><\/p>\n\n\n\n<p>-3<em>v<\/em>&nbsp;\u2212 15 =&nbsp;<\/p>\n<\/div><\/div>\n\n\n\n<p>Plug in v = \u20135 and simplify.<\/p>\n\n\n\n<p>\u20133v \u2212 15<\/p>\n\n\n\n<p>&nbsp;-3(<strong><sup>\u2013<\/sup>5<\/strong>)&nbsp;\u2212 15         <em>Plug in&nbsp;v&nbsp;=&nbsp;-5<\/em><\/p>\n\n\n\n<p>15 \u2212 15            <em>Multiply<\/em><\/p>\n\n\n\n<p>0                      <em>Subtract<\/em><\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group has-background has-normal-font-size\" style=\"background-color:#bfdbf0\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group has-background-background-color has-background\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<p class=\"has-text-color\" style=\"color:#b00012\"><strong>\ud83d\uddfc Evaluate the expression for&nbsp;<em>s<\/em>&nbsp;= 15.<\/strong><\/p>\n\n\n\n<p><em>-s<\/em>&nbsp;+ 6 =&nbsp;<\/p>\n<\/div><\/div>\n\n\n\n<p>Plug in s = 15 and simplify.<\/p>\n\n\n\n<p>-s + 6<\/p>\n\n\n\n<p>\u2013(15) + 6       Plug in s = 15<\/p>\n\n\n\n<p class=\"has-normal-font-size\">-15 + 6 Multiply<\/p>\n\n\n\n<p>-9 Add<\/p>\n<\/div><\/div>\n\n\n\n<p class=\"has-text-color has-large-font-size\" style=\"color:#d90000\">Let&#8217;s Practice!<\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/wordwall.net\/play\/76091\/698\/322\"><img loading=\"lazy\" decoding=\"async\" width=\"500\" height=\"500\" src=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/05\/Worksheet-1-3-23.png\" alt=\"\" class=\"wp-image-7336\" srcset=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/05\/Worksheet-1-3-23.png 500w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/05\/Worksheet-1-3-23-300x300.png 300w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/05\/Worksheet-1-3-23-150x150.png 150w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/a><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-full\"><a href=\"https:\/\/wordwall.net\/play\/76133\/520\/942\"><img loading=\"lazy\" decoding=\"async\" width=\"500\" height=\"500\" src=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/05\/Worksheet-1-1-2-24.png\" alt=\"\" class=\"wp-image-7337\" srcset=\"https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/05\/Worksheet-1-1-2-24.png 500w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/05\/Worksheet-1-1-2-24-300x300.png 300w, https:\/\/9thclass.deltapublications.in\/wp-content\/uploads\/2023\/05\/Worksheet-1-1-2-24-150x150.png 150w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><\/a><\/figure>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Evaluate variable expressions involving integers key notes : Understanding Variable Expressions Definition: Variables: Evaluating Variable Expressions Substitution: To evaluate a variable expression, substitute the given value(s) of the variable(s) into the expression and perform the arithmetic operations. Example: Evaluate 3x+4 for x=2. Order of Operations (PEMDAS): When evaluating expressions, always follow the order of operations:<a class=\"more-link\" href=\"https:\/\/9thclass.deltapublications.in\/index.php\/b-3-evaluate-variable-expressions-involving-integers\/\">Continue reading <span class=\"screen-reader-text\">&#8220;B.3 Evaluate variable expressions involving integers&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-30","page","type-page","status-publish","hentry","entry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages\/30","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/comments?post=30"}],"version-history":[{"count":33,"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages\/30\/revisions"}],"predecessor-version":[{"id":18251,"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/pages\/30\/revisions\/18251"}],"wp:attachment":[{"href":"https:\/\/9thclass.deltapublications.in\/index.php\/wp-json\/wp\/v2\/media?parent=30"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}