Question

How would you simplify `(2 sqrt 7 - 4 sqrt3)(4 sqrt 7 + 8 sqrt3)`?

Answer 1

-40

Explanation:

`(2sqrt(7)-4sqrt(3))(4sqrt(7)+8sqrt(3))`

You have to use the distributive operation of multiplication:

`2sqrt(7)xx4sqrt(7)+2sqrt(7)xx8sqrt(3)-4sqrt(3)xx4sqrt(7)-4sqrt(3)xx8sqrt(3)`

=`2xx4xx7+2xx8xxsqrt(7)xxsqrt(3)-4xx4xxsqrt(3)xxsqrt(7)-4xx8xx3`

=`56+16sqrt(21)-16sqrt(21)-96=-40`