Question

(√13-√ 7)(√ 13+√ 7) Помогите решить.

Answer 1

=(√13 )*2 -(√7)*2= 13-7=6

Answer 2

$(sqrt{13}-sqrt{7})(sqrt{13}+sqrt{7})=sqrt{13}*sqrt{13}+sqrt{13}*sqrt{7} \-sqrt{7}*sqrt{13}-sqrt{7}*sqrt{7}=13+(sqrt{13}*sqrt{7})-(sqrt{13}*sqrt{7})-7=\ 13-7=6$