(1,-9) , (9,-13)

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=-13-(-9)9-(1)

Simplify.

Simplify the numerator.

Multiply -1 by -9.

m=-13+99-(1)

Add -13 and 9.

m=-49-(1)

m=-49-(1)

Simplify the denominator.

Multiply -1 by 1.

m=-49-1

Subtract 1 from 9.

m=-48

m=-48

Reduce the expression by cancelling the common factors.

Cancel the common factor of -4 and 8.

Factor 4 out of -4.

m=4(-1)8

Cancel the common factors.

Factor 4 out of 8.

m=4⋅-14⋅2

Cancel the common factor.

m=4⋅-14⋅2

Rewrite the expression.

m=-12

m=-12

m=-12

Move the negative in front of the fraction.

m=-12

m=-12

m=-12

m=-12

Substitute the value of m into the slope-intercept form of the equation, y=mx+b.

y=(-12)⋅x+b

Substitute the value of x into the slope-intercept form of the equation, y=mx+b.

y=(-12)⋅(1)+b

Substitute the value of y into the slope-intercept form of the equation, y=mx+b.

-9=(-12)⋅(1)+b

Rewrite the equation as (-12)⋅(1)+b=-9.

(-12)⋅(1)+b=-9

Multiply -1 by 1.

-12+b=-9

Move all terms not containing b to the right side of the equation.

Add 12 to both sides of the equation.

b=-9+12

To write -9 as a fraction with a common denominator, multiply by 22.

b=-9⋅22+12

Combine -9 and 22.

b=-9⋅22+12

Combine the numerators over the common denominator.

b=-9⋅2+12

Simplify the numerator.

Multiply -9 by 2.

b=-18+12

Add -18 and 1.

b=-172

b=-172

Move the negative in front of the fraction.

b=-172

b=-172

b=-172

The values of the slope and y-intercept are m=-12 and b=-172.

m=-12

b=-172

Find the Slope and Y-Intercept (1,-9) , (9,-13)