Okay to find the answer is a bit of a pain, but I want to explain it to you. This way, you will understand how to do it next time.
Okay. We should start with the fact, all the angles of a triangle added together, adds up to 180 degrees. The equation to answer this would be...
(9x - 16) + (3x + 11) + (7x - 5) = 180
STEP 1: Combine like turns:
19x - 10 = 180
NEXT STEP(S): Get X alone on a single side:
x = 10
Please try to look at the beginning problem and work through it on your own (if you struggle when solving for x). Also, please read this entire thing. Have a good day; I hope this helped.
