How Do You Add Polynomials?

We can just drop the first set of parentheses because they doesn't have a negative sign in front
If there were a negative sign in front, we would have to distribute the negative before opening the parentheses
12a² and 4a² are like terms
-15a and -12a are also like terms
We're using the associative property to group like terms
Now we can just combine the like terms

1. Since we're just adding two groups of terms together, we can just drop the parentheses
1. Like terms are terms in a polynomial that have the same variables raised to the same degrees
1. There are no terms other than 6a³ that have 'a³' in them
2. 12a² and 4a² both have 'a²' in them, so they're like terms!
3. -15a and -12a both have just an 'a' raised to the first power, so they're like terms
4. There are no other constants, so 8 is by itself
1. We're using the associative property to group like terms
1. To combine like terms, we can just add together their coefficients
1. The coefficients are the numbers just in front of the variables
1. Now that all our terms are combined, we can rewrite everything as one single polynomial

Add the polynomials 6a3+12a2-15a and 4a2-12a+8