1) х-3у=1,
2ху-х^{2} + 9у^{2}=11-4х;
х=1+3у,
2(1+3у)-(1+3у)^{2} +9у^{2}=11-4(1+3у);
2+6у-(1+6у+9у^{2}) +9у^{2}=11-4-12у;
2+6у-1-6у-9у^{2} + 9у^{2}=11-4-12у;
12у=6;
у=2;
х=1+3*2,
х=7,
у=2.
1) х-3у=1,
2ху-х^{2} + 9у^{2}=11-4х;
х=1+3у,
2(1+3у)-(1+3у)^{2} +9у^{2}=11-4(1+3у);
х=1+3у,
2+6у-(1+6у+9у^{2}) +9у^{2}=11-4-12у;
х=1+3у,
2+6у-1-6у-9у^{2} + 9у^{2}=11-4-12у;
х=1+3у,
12у=6;
х=1+3у,
у=2;
х=1+3*2,
у=2;
х=7,
у=2.