{(х-1)(y+10) =9 {x-y=11

Question

{(х-1)(y+10) =9
{x-y=11

Answer 1

Точно не знаю, но по моему так:
{(11+y-1)(y+10)=9
{x-y=11
{21+2y-1=9
21+2y=1+9
21+2y=10
21+10=2y
31=2y
y=15.5
x-15.5=11
x=15.5+11
x=26.5