Step-by-step explanation:
In order to be like terms, the variables and exponents must be the same.
3a can be combined with 14a and 4a.
4b can be combined with 3b and 16b.
a² cannot be combined with any of the terms.
Expanded form is when you write a number using like the hundreds tens and ones places. Example: 521 = 500+20+1
