2х+3(х+у)=11 (знак системы) 7(х+3у)-6х=-59 помогите решить

[latex] left { {{2x+3(x+y)=11} atop {7(x+3y)-6x=-59}} ight. \ \ left { {{2x+3x+3y=11} atop {7x+21y-6x=-59}} ight. \ \ left { {{5x+3y=11} atop {x+21y=-59}} ight \ \ x=-59-21y \ \ 5(-59-21y)+3y=11 \ -295-105y+3=11 \ -102y=306 \ y=-3 \ \ x=-59-21*(-3)=-59+63=4 [/latex]