Question

только сократить,пожалуйсьа

Answer 1

А)$frac{x^2-7}{x+sqrt{7}}= frac{(x-sqrt{7})*(x+sqrt{7})}{x+sqrt{7}}=x-sqrt{7}$
Б)$frac{sqrt{14}-14}{2sqrt{7}-sqrt{42}}= frac{( sqrt{14}-14)*(2 sqrt{7}+ sqrt{42})}{-14}= frac{14*(sqrt{2}+sqrt{3}-2sqrt{7}-sqrt{42}}{-17}=-sqrt{2}-sqrt{3}+ \ \ +2sqrt{7} sqrt{42}$