Question

ecuaciones: x+2y = -2 3x-y=5 x+y=3 2x+2y=5

Answer 1

1) x + 2y = -2

3x - y = 5

3x - 5 = y

x + 2(3x-5) = 5

x + 6x - 10 = 5

7x = 5 + 10

x = 15/7

y = 3(15/7) - 5

y = 45/7 - 5

y = 10/7

2)

x + y = 3

x = 3 - y

2x + 2y = 5

2(3-y) + 2y = 5

6 - 2y + 2y = 5

0 = 5 - 6

0 = -1

no tiene solución