What is the length of the missing side of the larger triangle?

B

Step-by-step explanation:

Since the triangles are similar then the ratios of corresponding sides are equal, that is

= ( cross- multiply )

12 ? = 108 ( divide both sides by 12 )

? = 9 → B

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.