Question

(Корень3+Корень7) (2*Корень3-корень7)

Answer 1

$(sqrt{3}+ sqrt{7})( 2sqrt{3}- sqrt{7})= sqrt{3}* 2sqrt{3}-sqrt{3}*sqrt{7}+sqrt{7}*2sqrt{3}-sqrt{7}sqrt{7}= \ = 3*2-sqrt{3}sqrt{7}+2sqrt{3}sqrt{7}-7=6-7+sqrt{3}sqrt{7}=-1+sqrt{3}sqrt{7}$