Question

{х-у=-5/7
{4х+3у=-4 6/7

Answer 1

х - у = -5/7
4х + 3у = -34/7

у = х + 5/7
4х + 3х + 15/7 = -34/7

7х = -49/7
7х = -7
х = -1
у = -1 + 5/7 = -2/7
Ответ: х = -1; у = -2/7

Answer 2

$х=у-5/7 4(у-5/7)+3у=-4 6/7 4у+3у=20/7-4 6/7 7у=-14/7 7у=-2 у=-2/7 х=-2/7-5/7 х=-1$