How do you multiply #(3x^2 + 2y)(7x^2 + 3y)#?

1 Answer
Jul 26, 2016

#(3x^2 + 2y) (7x^2 + 3y)#

#21x^4 + 9x^2 y+ 14x^2y +6y^2#

#21x^4 + 23x^2y+6y#

Explanation:

Step 1
I multiplied
#3x^2# with #7x^2#
Step 2
I multiplied #3x^2# with #3y#.
So far we have #21x^4 + 9x^2y#
Step 3
I multiplied #2y# with #7x^2#
Step 4
I multiplied #2y# with #3y#.
We have #14x^2y + 6y^2#
Step 5
In total, we have #21x^4+9x^2y+14x^2y+6y^2#
Step 6
We combine like terms. You will see the only like terms are #9x^2y+14x^2y# Those are the only terms we combine.
Final Step
We combine everything
SO our answer is #21x^4+23x^2y+6y^2#