Question

Сделайте 5 номер ток!!

Answer 1

Ответ:

(12; 5)

Пошаговое объяснение:

$\dfrac{x!}{2!(x-2)!}=66\\\\ x(x-1)=132\\\\x^2-x-132=0\\\\D=1+528=529\\\\x=(1+23)/2=12$

$\dfrac{x!}{y!(x-y)!} =\dfrac{x!}{(y+2)!(x-y-2)!}\\\\ y!(x-y)!=(y+2)!(x-y-2)!\\\\(x-y-1)(x-y)=(y+2)(y+1)\\\\(11-y)(12-y)=(y+2)(y+1)\\\\132-23y+y^2=y^2+3y+2\\\\26y=130\\\\y=5$