Rozwiąż metodą podstawiania: a. 2x-y=10 x+5y=-17 b. 3x+y=9 2x-5y=-11

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b) \left \{ {{3x+y=9} \atop {2x-5y=-11}} \right. \left \{ {{y=9-3x} \atop {2x-5(9-3x)=-11}} \right. \left \{ {{y=9-3x} \atop {2x-45+15x=-11}} \right. \left \{ {{y=9-3x} \atop {17x-45=-11}} \right. \left \{ {{y=9-3x} \atop {17x=34}} \right. \left \{ {{y=9-3x} \atop {x=2}} \right. \left \{ {{y=9-3\cdot 2} \atop {x=2}} \right. \left \{ {{y=9-6} \atop {x=2}} \right. \left \{ {{y=3} \atop {x=2}} \right.