Question

What is the equation in point-slope form if a line that passes through points (3,-5) and (-8,4)?

A) y-4=-1/5(x+8)
B) y+4 = -9/11(x-8)
C) y-4= -9/11(x+8)
D) y+4= -1/5(x-8)

Answer 1

The slope-point formula:

$y-y_1=m(x-x_1)\\\\m=\dfrac{y_2-y_1}{x_2-x_1}$

We have (3, -5) and (-8, 4).

Substitute:

$m=\dfrac{4-(-5)}{-8-3}=\dfrac{9}{-11}=-\dfrac{9}{11}\\\\y-4=-\dfrac{9}{11}(x-(-8))\\\\y-4=-\dfrac{9}{11}(x+8)\to C)$