9. The model represents an equation. Х
-1
х
-1
1
х
-1
-1
-5x
What value of x makes the equation true? 8.8C
A. X = 3
B. X=-3
C. X = 2
D. X = -2

abde or 1,2,4, 5 is the answer

step-by-step explanation:

2

step-by-step explanation:

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.