# Find the Slope and Y-Intercept (-4,5) , (9,20) (-4,5) , (9,20)
Find the value of the slope.
Slope is equal to the change in y over the change in x, or rise over run.
m=change in ychange in x
The change in x is equal to the difference in x-coordinates (also called run), and the change in y is equal to the difference in y-coordinates (also called rise).
m=y2-y1x2-x1
Substitute in the values of x and y into the equation to find the slope.
m=20-(5)9-(-4)
Simplify.
Simplify the numerator.
Multiply -1 by 5.
m=20-59-(-4)
Subtract 5 from 20.
m=159-(-4)
m=159-(-4)
Simplify the denominator.
Multiply -1 by -4.
m=159+4
m=1513
m=1513
m=1513
m=1513
Find the value of the y-intercept.
Substitute the value of m into the slope-intercept form of the equation, y=mx+b.
y=(1513)x+b
Substitute the value of x into the slope-intercept form of the equation, y=mx+b.
y=(1513)⋅(-4)+b
Substitute the value of y into the slope-intercept form of the equation, y=mx+b.
5=(1513)⋅(-4)+b
Rewrite the equation as (1513)⋅(-4)+b=5.
(1513)⋅(-4)+b=5
Simplify each term.
Multiply (1513)(-4).
Combine 1513 and -4.
15⋅-413+b=5
Multiply 15 by -4.
-6013+b=5
-6013+b=5
Move the negative in front of the fraction.
-6013+b=5
-6013+b=5
Move all terms not containing b to the right side of the equation.
Add 6013 to both sides of the equation.
b=5+6013
To write 5 as a fraction with a common denominator, multiply by 1313.
b=5⋅1313+6013
Combine 5 and 1313.
b=5⋅1313+6013
Combine the numerators over the common denominator.
b=5⋅13+6013
Simplify the numerator.
Multiply 5 by 13.
b=65+6013
b=12513
b=12513
b=12513
b=12513
The values of the slope and y-intercept are m=1513 and b=12513.
m=1513
b=12513
Find the Slope and Y-Intercept (-4,5) , (9,20)     