Respuesta :

Answer:

C. 11

Step-by-step explanation:

(4x + 18) + (8x + 30) = 180

Combine like terms

12x + 48 = 180

Subtract 48 from both sides

12x = 132

Divide both sides by 12

x = 11

X = 11

Both equations given are supplementary, meaning that they add up to 180, so set them equal to 180 and solve.

(8x + 30) + (4x + 18) = 180

12x + 48 = 180

12x = 132

x = 11