Answer:
m = 3; b = -12
Explanation:
In order to answer the question definitively, we must assume you intend for the equation to be an identity.
6(2x -5) -(mx +2) = 9x +b
12x -10 -mx -2 = 9x +b
Equating x terms:
12x -mx = 9x
12 -m = 9 . . . . . . divide by x; next, add m-9
12 -9 = m = 3
Equating constant terms:
-10 -2 = b
-12 = b