Question

Спростіть вираз(7-4√5)(2+√5)^2(7+4√5)

Answer 1

$(7-4sqrt{5})(2+sqrt{5})^2(7+4sqrt{5})=(49-16cdot5)(2+sqrt{5})^2=-31(2+sqrt{5})^2=\ \ \ =-31cdot(4+4sqrt{5}+5)=-31cdot(9+4sqrt{5})=-279-124sqrt{5}$

Answer 2

I hope this helps you