Slope-intercept form: find the slope and y-intercept
Key Notes:
The y-intercept is the y-coordinate of the point where the graph crosses the y-axis.
If a line crosses the y-axis at the point (0, y), then y is the y-intercept.
In slope-intercept form (y = mx + b), the y-intercept is b.
In the equation y = mx + b, m is the slope.
Learn with an example
Find the y-intercept of the following equation. Simplify your answer.
y = 2x − 8
The y-intercept is on the y-axis, where x = 0. Plug x = 0 into the equation and solve for y.
y = 2x − 8
y = 2(0) − 8
y = –8 Simplify
The y-intercept is – 8.
Since the equation is in slope-intercept form (y = mx + b), you can also find the y-intercept by looking for b, the y-intercept.
y = mx + b
y = 2x + –8
Again,they-intercept is–8.
Find the slope of the line y = 9/2 x + 1/2
Find the slope, m:
y = mx + b
y =9/2 x + 1/2
The slope is 9/2.
Find the y-intercept of the following equation. Simplify your answer.
y = 6x + 5
y-intercept =
The y-intercept is on the y-axis, where x = 0. Plug x = 0 into the equation and solve for y.
y = 6x + 5
y = 6(0) + 5 Plugin x = 0
y = 5 Simplify
The – intercept is 5.
Since the equation is in slope-intercept form (y = mx + b), you can also find the y-intercept by looking for b, the y-intercept.
y = mx + b
y = 6x + 5
Again, they – intercept is 5.
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