Suma y resta: 3x+4Y=10 2x+5Y=5
3x +4y =10 *2
2x + 5y = 5 * -3
6x + 8y =20
-6x -15y = -15
-7y=5
y=-5/7
2x +5(-5/7)=-15
2x=-15+25/7
x=((-105+25)*2)/7
x=-160/7
