Answer:
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 <===
