Verified answer

[tex]\displaystyle\bf\\\left \{ {{2(4x-5)-3(3+4y)=5} \atop {7(6y-1)-(4+3x)=21y-86}} \right. \\\\\\\left \{ {{8x-10-9-12y=5} \atop {42y-7-4-3x=21y-86}} \right.\\\\\\\left \{ {{8x-12y=5+10+9} \atop {-3x+42y-21y=-86+7+4}} \right. \\\\\\\left \{ {{8x-12y=24 \ |:4} \atop {-3x+21y=-75} \ |:1,5} \right. \\\\\\+\left \{ {{2x-3y=6} \atop {-2x+14y=-50}} \right. \\------------\\11y=-44\\\\y=-44:11=-4\\\\2x=6+3y=6+3\cdot (-4)=6-12=-6\\\\x=-6:2=-3\\\\Otvet \ : \ \Big(-3 \ ; \ -4\Big)[/tex]