What is 8b - ab + 7 subtracted from 3a - 9ab + b?

To find the correct solution, first we need to correctly execute the operation of subtraction indicated in the problem, which requires us to subtract the expression ( 8b - ab + 7 ) from ( 3a - 9ab + b ).

Start by rewriting the subtraction: [ (3a - 9ab + b) - (8b - ab + 7) ]

Distributing the minus sign to the second expression gives us: [ 3a - 9ab + b - 8b + ab - 7 ]

Now, combine the like terms step-by-step:

1. For the ( a ) terms, we have: [ 3a ]

2. For the ( ab ) terms, combine ( -9ab ) and ( ab ): [ -9ab + ab = -8ab ]

3. For the ( b ) terms, combine ( b ) and ( -8b ): [ b - 8b = -7b ]

4. Finally, include the constant term, which is ( -7 ).

Now, putting all those results together, we form the complete expression: