Question

Which equation is the equation of the line, in point-slope form, that has a slope of -4 and passes through the point (7,1)

Answer choices:

A. y-7 = 4(x-1)

B. y-1 = -4(x+7)

C. y-1 = -4(x-7)

D. y-7 = -4(x-1)

Answer 1

y – y1 = m(x – x1)

First, you have to find m, or the slope.

This is

y - y

-------

x - x

It doesn't matter which way you put it in, but I'm going to do it like this:

-10 - (-8)

-------------

-7 - (-6)

This reduces into:

-2/-1 = 2

Now, it'll look like this (according to your answer choices, but you can use the other coordinate, also):

y - (-10) = 2(x - (-7))

This turns into:

y + 10 = 2(x + 7)

This answer is: C.