Решите систему уравнений 7х-5у=–2 х+у=1 3/35

[latex] \left \{ {{7x-5y=-2} \atop {x+y= \frac{13}{35} }} \right. \\ \\ \left \{ {{7x-5y=-2} \atop {x= \frac{13}{35}-y }} \right. \\ \\ 7*( \frac{13}{35}-y)-5y=-2 \\ \frac{13}{5}-7y-5y=-2 \\ -12y=-2- \frac{13}{5} \\ -12y=- \frac{23}{5} \\ \\ y= \frac{23}{5}: \frac{12}{1}= \frac{23}{5}* \frac{1}{12}= \frac{23}{60} \\ \\ x+ \frac{23}{60}= \frac{13}{35} \\ \\ x= \frac{13}{35}- \frac{23}{60}= \frac{780-805}{2100} = \frac{25}{2100}= \frac{1}{84} [/latex]