Answer:
x = 83.2
Step-by-step explanation:
Let the unknown number be x
-90 * (x - 83) = x + (-99)
-90x + 7470 = x - 99
Subtract x from both sides
-90x - x + 7470 = x - x - 99
-91x + 7470 = -99
Subtract 7470 from both sides
-91x + 7470 - 7470 = -99 -7470
-91x = -7569
Divide both sides by -91
x = 83.2
