Is there supposed to be parentheses?
Answer:
x = 15 or x = -19
Step-by-step explanation:
ΔPQR similar to ΔSQT
SQ / QP = ST / PR
8 / 8+x+5 = x-9 / 21
8 / 13+x = x-9 / 21
(x+13)(X-9) = 168
x² + 4x - 117 = 168
x² + 4x - 285 = 0
(x - 15) (x + 19) = 0
x = 15 or x = -19
Answer is D. 14
3 times 6 is 18 and minus 4 is 14