Does anyone know how to multiply (3√3-9√7)(4√3+12√7)?

Question

Does anyone know how to multiply (3√3-9√7)(4√3+12√7)?

Answer 1

(3√3-9√7)(4√3+12√7)

=3√3 x 4√3+3√3 x 12√7-(9√7 x 4√3)-(9√7x 12√7)

=36+36√21-36√21-756

=36-756

= -720

:))

Answer 2

take 3 common out from the first bracket, and take 4 common out from the second bracket. :

=   3 * 4 *    [ (√3-3√7) * (√3+3√7)  ]

=   12 * [   (3 - 9*7)  ]

Answer 3

(3√3-9√7)(4√3+12√7)

=3√3.4√3 + 3√3.12√7 - 9√7.4√3 - 9√7.12√7

=12√9 + 36√21 - 36√21 - 108√49

=36 - 756

=-720