( √7 - √12)( √ 7 - 3√3)

Question

( √7 - √12)( √ 7 - 3√3)

Answer 1

( √7 - √12)( √ 7 - 3√3)=(√7)^2- 3√21-√84+3√36=7-3√21 - √84+12=19-3√21 - 2√21=19-√21