If QR = x + 10, RS = 8, and QS = 7x, what is QS?

Question

q x+10 r 8 s

7x

Answer 1

Remember that QS = QR + RS

so

7x = (x + 10) + 8 (QS = QR + RS)

7x = x + 18 ( simplify)

6x = 18 (subtract x from each side)

x = 3 (divide both sides by 6)

The question was QS. QS = 7(3) = 21.

You can check your answer by substituting x back in and you get 21 = 13 + 8 21=21.