Question

This table gives a few (x,y) pairs of a line in the coordinate plane.

x | y
-21 | -64
-15 | -48
-9 | -32


What is the x-intercept of the line?
-
please help!

Answer 1

Explanation:

slope m = Δy / Δx = (-64 - (-32)) / (-21 - (-9)) = -32/-12 = 8/3

y = (8/3)x + b

-48 = (8/3)(-15) + b

-48 = -40 + b

b = - 8

y = (8/3)x - 8

x intercept occurs where y = 0

0 = (8/3)x - 8

8 = (8/3)x

x = 3

(3, 0)