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 - 5y = 48

Answer 1

(C) -7x - 5y = -48

Step by step explanation:

We look for the equation of the line AB

We have then:

y-yo = m (x-x0)

m = (y2-y1) / (x2-x1)

m = (4 - (- 1)) / (4 - (- 3))

m = 5/7

We choose an ordered pair:

(xo, yo) = (4, 4)

Substituting:

y-4 = (5/7) (x-4)

y = (5/7) x-20/7 + 4

7y = 5x - 20 + 28

7y = 5x + 8

y = (5/7) x + 8/7

The equation of the perpendicular line is:

-7x - 5y = -48