Системы уравнений. Срочно! 50 баллов.

Решите задачу:

$\left \{ {{2x-3y=11|*(-2)} \atop {4x+5y=-11}} \right. \left \{ {{-4x+6y=-22} \atop{4x+5y=-11}} \right. \left \{ {{11y=-33} \atop {2x-3y=11}} \right. \left \{ {{y=-3} \atop {2x-3*(-3)=11}} \right. \left \{ {{y=-3} \atop {2x+9=11}} \right.$

$\left \{ {{y=-3} \atop {2x=2}} \right. \left \{ {{y=-3} \atop {x=1}} \right.$

$\left \{ {{3x+7y=2|*5} \atop {2x-5y=1|*7}} \right. \left \{ {{15x+35y=10} \atop {14x-35y=7}} \right. \left \{ {{29x=17} \atop {3x+7y=2}} \right. \left \{ {{x= \frac{17}{29} } \atop {3* \frac{17}{29}+7y=2 }} \right. \left \{ {{x= \frac{17}{29} } \atop { 1\frac{22}{29}+7y=2 }} \right. \left \{ {{x= \frac{17}{29} } \atop { 7y= \frac{7}{29} }} \right.$

$\left \{ {{x= \frac{17}{29} } \atop { y= \frac{1}{29} }} \right.$

$( \frac{27}{29} ; \frac{1}{29})$

$\left \{ {{ \frac{1}{5}(x+y)=2 } \atop { \frac{1}{2}(x-y)=1 }} \right. \left \{ {{x+y=10 } \atop { x-y=2 }} \right. \left \{ {{2x=12} \atop {x+y=10}} \right. \left \{ {{x=6} \atop {6+y=10}} \right. \left \{ {{x=6} \atop {y=4}} \right.$