(-15,-8) , (-18,-12)

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=-12-(-8)-18-(-15)

Simplify.

Simplify the numerator.

Multiply -1 by -8.

m=-12+8-18-(-15)

Add -12 and 8.

m=-4-18-(-15)

m=-4-18-(-15)

Simplify the denominator.

Multiply -1 by -15.

m=-4-18+15

Add -18 and 15.

m=-4-3

m=-4-3

Dividing two negative values results in a positive value.

m=43

m=43

m=43

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

y=(43)x+b

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

y=(43)⋅(-15)+b

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

-8=(43)⋅(-15)+b

Rewrite the equation as (43)⋅(-15)+b=-8.

(43)⋅(-15)+b=-8

Simplify each term.

Cancel the common factor of 3.

Factor 3 out of -15.

43⋅(3(-5))+b=-8

Cancel the common factor.

43⋅(3⋅-5)+b=-8

Rewrite the expression.

4⋅-5+b=-8

4⋅-5+b=-8

Multiply 4 by -5.

-20+b=-8

-20+b=-8

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

Add 20 to both sides of the equation.

b=-8+20

Add -8 and 20.

b=12

b=12

b=12

The values of the slope and y-intercept are m=43 and b=12.

m=43

b=12

Find the Slope and Y-Intercept (-15,-8) , (-18,-12)