\left \{ {{5x-5y=10} \atop {3x-7y=20-2x-2y)}} \right. " alt="\left \{ {{5(x-y)=10} \atop {3x-7y=20-2(x+y)}} \right. => \left \{ {{5x-5y=10} \atop {3x-7y=20-2x-2y)}} \right. " align="absmiddle" class="latex-formula">
=.
\left \{ {{x-y=2} \atop {5x-5y=20}} \right. => \left \{ {{x=y+2} \atop {x-y=4}} \right. => \left \{ {{x=y+2} \atop {x=4+y}} \right. " alt="=> \left \{ {{x-y=2} \atop {5x-5y=20}} \right. => \left \{ {{x=y+2} \atop {x-y=4}} \right. => \left \{ {{x=y+2} \atop {x=4+y}} \right. " align="absmiddle" class="latex-formula">
Данная система уравнений не имеет решений.