Question

$(3 sqrt{11}-4)(3 sqrt{11} +4)$

Answer 1

$(a)^2-(b)^2=[(a)-(b)]*[(a)+(b)]$

$a=3 sqrt{11}$ and $b=4$

$(3 sqrt{11}-4)(3sqrt{11}+4)=[(3 sqrt{11} )-(4)]*[( 3sqrt{11} )+(4)]=$

$=(3 sqrt{11} )^2-(4)^2=3^2*( sqrt{11} )^2-4^2=9*11-16=99-16=83$