Question

Помогите решить уравнение с факториалами. Пожалуйста, срочно((

Answer 1

$left { {{frac{x!}{(x-y)!}=10cdot frac{x!}{(x-(y-1))!}, } atop {3cdot frac{x!}{y!(x-y)!}=5cdot frac{x!}{(y-1)!(x-(y-1))!}}} right.\\a); ; frac{x!}{(x-y)!}=10cdot frac{x!}{(x-(y-1))!}; ; to ; ; frac{1}{(x-y)!}=frac{10}{(x-(y-1))!}; ; ,\\1=frac{10cdot (x-y)!}{(x-y+1)!}; ; ,; ; 1=frac{10}{x-y+1}; ; ,; ; x-y+1=10\\b); ; 3cdot frac{x!}{y!(x-y)!}=5cdot frac{x!}{(y-1)!(x-(y-1))!}; ; to ; ; frac{3}{y!(x-y)!} =frac{5}{(y-1)!(x-y+1)!}$

$frac{3}{5}=frac{y!(x-y)!}{(y-1)!(x-y+1)!} ; ,; ; frac{3}{5}=frac{y}{x-y+1}; ,; ; 5y=3(x-y+1); ,\ \5y=3cdot 10; ; to ; ; y=6\\x-y+1=10; ; to ; ; x=10+y-1=10+6-1=15\\Otvet:; ; x=15; ,; y=6.\\\star ; ; y!=(y-1)!, cdot y; ; star \\star ; ; (x-y+1)!=(x-y)!, cdot (x-y+1); ; star$