Respuesta :

3x = 10.........................?

You're solving for x, so solve one equation for y first.
3x + 2y = 3
2x - 2y = 7

2x - 2y = 7
2x = 2y + 7
2x - 7 = 2y
y = (2x - 7)/2
Plug it into the other equation;
3x + 2((2x - 7)/2) = 3
3x - 2x - 7 = 3
x - 7 = 3
x = 10