Answer:
x = 10.
Step-by-step explanation:
(5x-1) + (8x+5) + (4x+6) = 180 (the 3 angles in a triangle sum to 180 degrees).
5x + 8x+ 4x - 1 + 5 +6 = 180
17x + 10 = 180
17x = 170
