Question

{−2x+7y=−7 −5x+14y=−7

Answer 1

Answer: $x=-7$, $y=-3$

Step-by-step explanation:

$\left \{ {-2x+7y=-7} \atop {-5x+14y=-7} \right.$

multiply 2 at $-2x+7y=-7$

$-4x+14y=-14$

subtract $-4x+14y=-14$ and $-5x+14y=-7$

$x=-7$

put $x=-7$ at $-2x+7y=-7$

$7y=-21, y=-3$

Answer 2

Answer: x=7, y=2

Step-by-step explanation:

1. -2(-2x+7y=-7) -> 4x-14y=14

2. 4x-14y=14

   -5x+14y=-7

3. -x = 7, x=7

4. -5(7)+14y=-7

5. -35+14y=-7

6. 14y=28, y=2