Question

Select the pair of equations whose graphs are perpendicular.

(Points : 5)
a 5x – 8y = 9
12x – 5y = 7
b x + 6y = 8
y = 2x – 8
c y = 2x – 7
x + 2y = 3
d 2y = –3x + 5
2x + 3y = 4
i think it d im i correct

Answer 1

First thing you want to do is put them into slope intercept form.

A.) 5x-8y=9 (y=-1 1/8+5/8x) 12x-5y=7 (y=-1 2/5+2 2/5x)

B.) x+6y=8 (y=1 2/6-1/6x) (y=2x-8)

C.) x+2y=3 (y=1.5-1/2x) (y=2x-7)

D.) 2y=-3x+5 (y=-3/2x+2.5) 2x+3y=4 (y=1 1/3-2/3x)

Then, to determine if two equations are perpendicular they must have slopes that are opposite reciprocal. For example 7 and -1/7. the only one that fits that description is C.