Answer:
3a^3
Explanation:
Ok I got you bud now the the first thing to notice that they're all the same variable. so the way I learned to look at is like this
1a^2 x 3a^1
so the reason I put it like this is so I remember that in front of every variable is a coefficient. so you would first multiply the coefficient
3x1=3
3
then multiply the a's you have one a that is being squared and one a to the first power so since your multiplying them you just add the exponents
a^1 + a^2 = a^3
so when you put it all together it says 3a^3
hope this helps