Question

помогите с 3 и 4 номером))))

Answer 1

$(7^{0.5}-3^{0.5})^2+(7^{0.5}+3^{0.5})^2=7-21^{0.5}+3+7+21^{0.5}+3=20$

$cfrac{x-y}{x^{0.5}-y^{0.5}}= cfrac{(x^{0.5}-y^{0.5})(x^{0.5}+y^{0.5})}{x^{0.5}-y^{0.5}}= x^{0.5}+y^{0.5}$