Combine the like terms to simplify the expression. 4a^2+7b^2+5b^2-a

Step-by-step explanation:

before we start, like terms have to have the EXACT same variable and exponent.

4a^2 + 7b^2 + 5b^2 - a

gather like terms ...

4a^2 ... no other like term

7b^2 + 5b^2 = 12b^2

-a ... no other like terms

just because they dont have like terms, dont forget them

so we end up with : 4a^2 + 12b^2 - a <===