Question

x+2y=5
-2x+y=-5


resolver por igualacion

Answer 1

X + 2Y = 5  -->  Y = (5 - X) / 2
-2X + Y = -5  -->  Y = 2X - 5

Igualamos a Y:
(5 - X) / 2 = 2X - 5
5 - X = 4X - 10
10 + 5 = 4X + X
15 = 5X
X = 15/5 = 3
X = 3.

En: Y = 2X - 5.  Sustituimos X:
Y = 2×3 - 5 = 1
Y = 1.