Question

решите систему уравнений методом сложения

4x+7y=18
6x+11y=10 ;

Answer 1

$\displaystyle\bf\\\left \{ {{4x+7y=18} \ |\cdot(-3)\atop {6x+11y=10} \ |\cdot 2} \right. \\\\\\+\left \{ {{-12x-21y=-54} \atop {12x+22y=20}} \right. \\------------\\y=-34\\\\4x=18-7y=18-7\cdot(-34)=18+238=256\\\\x=256:4=64\\\\Otvet:(64 \ ; \ -34)$