Solve 10*a - 5*a = -15 for a.
Solve this plz.

A: -3

Solve -98*u + 1249 = 192*u + 769 - 4160 for u.
Solve this plz.

A: 16

Solve -10*x - 69 = -25*x - 324 for x.
Solve this plz.

A:
-17