Slope-intercept form: write an equation
Key Notes:
The slope-intercept form of a linear equation is
y = mx + b
where m is the slope and b is the y-intercept.
Learn with an example
A line’s y-intercept is 16, and its slope is 8. What is its equation in slope-intercept form?
Plug the slope m = 8 and the y-intercept b = 16 into the slope-intercept formula.
y = mx + b
y = 8x + 16
y = 8x − 16
The equation of the line in slope-intercept form is y = 8x − 16.
A line’s slope is 1, and its y-intercept is 19. What is its equation in slope-intercept form?
Plug the slope m = 1 and the y-intercept b = 19 into the slope-intercept formula.
y = mx + b
y = 1x + 19
y = x + 19
The equation of the line in slope-intercept form is y = x + 19.
There is a line whose y-intercept is 20 and whose slope is 1. What is its equation in slope-intercept form?
Plug the slope m = 1 and the y-intercept b = 20 into the slope-intercept formula.
y = mx + b
y = 1x + 20
y = x + 20
y = x − 20
The equation of the line in slope-intercept form is y = x − 20.
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