How do you simplify (x + 7)(x - 7)(x+7)(x7)?

1 Answer
Jul 19, 2016

x^2 -49x249

Explanation:

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

(x+7)(x-7)(x+7)(x7)

=x^2 -7x + 7x - 49" which will now simplify"x27x+7x49 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 -49x249