Question

.....?????...........

Answer 1

You need 3a^3 to equal a^3, so you would need at subtract 2a^3.

Since the problem is addition, add - 2a^3:

3a^3 + -2a^3 = 3a^3 - 2a^3 = a^3

Then you have -5b^3 and you need it to equal b^^3, so you would need to add 6b^3:

-5b^3 + 6b^3 = b^3

First box would be -2

Second box would be 6