Answer:
10a²b² -8a²b +6ab² -4ab +7
Step-by-step explanation:
If P represents the given polynomial (sum), and A represents the unknown addend, it appears you have ...
A + (-5) = P
You want to find A. You can do that by adding 5 to both sides of this equation:
A = P +5
Adding 5 to the given polynomial gives you ...
10a²b² -8a²b +6ab² -4ab +7 . . . . the other addend
