How do you find the product of #(3+7v^2)(3-7v^2)#?

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Answer 1 · 2016-07-22T15:53:53

#9-49v^4#

This is a binomial #xx# a binomial.

Each term in the first bracket must be multiplied by each term in the second bracket. This will give #2xx2 = 4# terms.

#(3+7v^2)(3-7v^2)#

= #9 -21v^2 +21v^2 -49v^4#

The middle terms are additive inverses, leaving us with..

#9-49v^4#

We could also have recognised this as the factors of the Difference of two squares (the brackets are the same apart from the signs),

and written down the two squares immediately.