# Find the Slope and Y-Intercept (4,5) , (8,-8) (4,5) , (8,-8)
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=-8-(5)8-(4)
Simplify.
Simplify the numerator.
Multiply -1 by 5.
m=-8-58-(4)
Subtract 5 from -8.
m=-138-(4)
m=-138-(4)
Simplify the denominator.
Multiply -1 by 4.
m=-138-4
Subtract 4 from 8.
m=-134
m=-134
Move the negative in front of the fraction.
m=-134
m=-134
m=-134
Find the value of the y-intercept.
Substitute the value of m into the slope-intercept form of the equation, y=mx+b.
y=(-134)⋅x+b
Substitute the value of x into the slope-intercept form of the equation, y=mx+b.
y=(-134)⋅(4)+b
Substitute the value of y into the slope-intercept form of the equation, y=mx+b.
5=(-134)⋅(4)+b
Rewrite the equation as (-134)⋅(4)+b=5.
(-134)⋅(4)+b=5
Cancel the common factor of 4.
Move the leading negative in -134 into the numerator.
-134⋅4+b=5
Cancel the common factor.
-134⋅4+b=5
Rewrite the expression.
-13+b=5
-13+b=5
Move all terms not containing b to the right side of the equation.
Add 13 to both sides of the equation.
b=5+13
b=18
b=18
b=18
The values of the slope and y-intercept are m=-134 and b=18.
m=-134
b=18
Find the Slope and Y-Intercept (4,5) , (8,-8)     