How do you simplify #(x + 7)(x - 7)#?

1 Answer
Jul 19, 2016

Answer:

#x^2 -49#

Explanation:

There are 2 binomials to be multiplied. This can be done by usual distributive method :

#(x+7)(x-7)#

=#x^2 -7x + 7x - 49" which will now simplify"#

OR we should be able to instantly recognise that these are the factors which would be obtained by factoring the difference of two squares/ (The brackets are the same except for the signs)

Either method will lead to the result of
#x^2 -49#