Question

Write an equation of the line that passes through the points (5, -7) and (3, -1).

Answer 1

Answer:

y = -3x + 8

Step-by-step explanation:

I like to recommend this particular method for finding the slope of a  line through two given points:

Notice that if we move from (3, -1) to (5, -7), the horizontal distance covered (the "run") is 2 and the vertical change (the "rise") is -6.  Thus, the slope is m = rise / run = -6 / 2, or -3.

Starting with y = mx + b, replace y with -7 and x with 5, and m with -3:

-7 = -3(5) + b    ...  we must find b.

-7 = -15 + b    yields b = 8

and so the equation of this line is y = -3x + 8.