Question

Explain why 2a+3b=5ab

Answer 1

they can’t the variables have to be the same in order to add or subtract

Answer 2

That's not correct. The terms 2a and 3b are not like terms, so we cannot combine them to get 5ab. We simply leave it as 2a+3b.

If you had 2a+3a, then it would simplify to 5a

Similarly, 2b+3b = 5b

Or you could have 2ab+3ab = 5ab

The key is that the variable portions must match up to be able to add them.