{2x+(x-y)/4=11
{3y-(x-y)/3=1
{8x+x-y=44
{9y-x+y=3
{9x-y=44
{-x+10y=3 ⇒x=10y-3
9(10y-3)-y=44
90y-27-y=44
89y=44+27=71
y=71/89
x=10*71/89-3=443/89=4 87/89
ответ (443/89;71/89)
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5x-(x-y)/5=11
2y-(x+y)/3=11
25x-x+y=55
6y-x-y=33
24x+y=55
5y-x=33 ⇒ x=5y-33
24(5y-33)+y=55
120y-792+y=55
121y=847
y=847/121=7
x=5*7-33=35-33=2
ответ (2;7)