Question

Решите систему уравнений
3х - у = -1
-х + 2у = 7

Answer 1

$\left \{ {{3x-y=-1} \atop {-x+2y=7|\cdot 3}} \right. \; \oplus \; \left \{ {{3x-y=-1} \atop {5y=20}} \right. \; \; \left \{ {{3x=-1+4} \atop {y=4}} \right. \; \; \left \{ {{x=1} \atop {y=4}} \right. \\\\Otvet:\; \; (1,4)\; .$