6a - 3a - 2a + 45 = 81

Simplify the left side of the equation by combining like terms:

6a - 3a - 2a = a

a + 45 = 81

Subtract 45 from both sides of the equation:

a = 81 - 45
a = 36

Therefore, the solution to the first equation is a = 36.

7b + 4b - 10b - 37 = 54

Simplify the left side of the equation by combining like terms:

7b + 4b - 10b = b

b - 37 = 54

Add 37 to both sides of the equation:

b = 54 + 37
b = 91

Therefore, the solution to the second equation is b = 91.