Answer: a = 1, b = 0, c = -36
Explanation:
Move everything to one side so zero is on the other side.
Then you have it in the form: ax² + bx + c = 0
x² - 86 = -50
+50 +50
x² - 36 = 0
Notice that there is no "x" term so its coefficient is zero.
1x² + 0x - 36 = 0
↓ ↓ ↓
a=1 b=0 c=-36