-104 = -2(2 + 6r) - 4

r= 9.3333333 (repeating)

Step-by-step explanation:

-104= -4-12r-4

-12r-8= -104

-12r= -112

r= -112/-12

r= 9.3333333 (repeating)

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.