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

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

Substitute:

`m=(4-(-5))/(-8-3)=(9)/(-11)=-(9)/(11)\\\\y-4=-(9)/(11)(x-(-8))\\\\y-4=-(9)/(11)(x+8)\to C)`