Помогите решить. Даю 15 баллов.
{х+2у=-1, {|х-у|=2; 1){х+2у=-1, {х - у= 2; 3у=-3; у=-1; х+2(-1)=-1; х=1; (1; -1); 2){х+2у=-1, {-(х-у)=2; {х+2у=-1, {-х+у=2; 3у=1; у=1/3; х+2(1/3)=-1; х=-1-2/3; х=-1 2/3. (-1 2/3; 1/3).