What is the slope-intercept form of the line passing through (-2, -1) and (-1, 7) ?

1 Answer
Dec 17, 2015

y=8x+15

Explanation:

The slope-intercept form of a line can be represented by the equation:

y=mx+b

Start by finding the slope of the line, which can be calculated with the formula:

m=(y_2-y_1)/(x_2-x_1)

where:
m=slope
(x_1, y_1)=(-2, -1)
(x_2, y_2)=(-1, 7)

Substitute your known values into the equation to find the slope:

m=(y_2-y_1)/(x_2-x_1)

m=(7-(-1))/(-1-(-2))

m=8/1

m=8

So far, our equation is y=8x+b. We still need to find b, so substitute either point, (-2,-1) or (-1,7) into the equation since they are both points on the line, to find b. In this case, we will use (-2,-1):

y=8x+b

-1=8(-2)+b

-1=-16+b

b=15

Substitute the calculated values to obtain the equation:

y=8x+15