Question

AB and BC form a right angle at point B. If A=(-3,-1) and B=(4,4), what is the equation of BC

A. X+3y=16
B. 2x+y=12
C. -7x-5y=-48
D. 7x-5=48

Answer 1

Answer: D. -7x-5y=-48

Explanation:

The slope of AB is
`(-1-4)/(-3-4)=(5)/(7)`. Since perpendicular lines have slopes that are negative reciprocals, the slope of BC is -7/5.

Substituting into point-slope form,

`y-4=-(7)/(5)(x-4)\\\\5y-20=-7(x-4)\\\\5y-20=-7x+28\\\\\boxed{-7x-5y=-48}`