Stephanie B. answered 10/24/12
Math, Science and Language Tutor
Problem: 12a4b - 7a2b2 + 8ab3 -6a4b - 5a2b2 + 3ab3
Answer: We want to look at those terms that have the same variable and exponent. They need to match.
Let's make first put these in order, bunching all the like terms.
12a4b - 6a4b + 8ab3 + 3ab3 - 7a2b2 - 5a2b2
Do you see how the colored variables are the same? Because they are the same, we only need to perform the operations on the coefficients.
Let's add these up. Remember, group like terms.
= (12-6)a4b + (8+3)ab3 + (-7-5)a2b2
= 6a4b + 11ab3 - 12a2b2
Final answer. Do you see how we can't go any further? None of the variables are the same, and so we stop here.
Hope this helps
Stephanie