6x+21+15-2x
4x+36
hope this helps...
Act like it's a rectangle. The height is 10 because 7+3=10 and the length it 27. Multiply them for the are and you get 270 in. Then multiply 6x7=42 because that's the are of the space that is missing from the imaginary rectangle. Multiply by 2 (84 in.) because there are 2 missing spaces and subtract from 270= 186 inches is your answer.
The firs t res is x=4
the second is D