Question

Substitusikan x + 2y -5 = 0 ||| 2x + y + 2 = 0

Answer 1

X+2y = 5 ---> 2x + 4y = 10
2x+y = -2 ---> 2x + y = -2 -

3y = 12
y = 4

x + 8 = 5
x = -3

Answer 2

X + 2y - 5 = 0  II x + 2y = 5  I x 2 II 2x + 4 y = 10
2x + y + 2 = 0 II 2x + y = -2 I x 1 II 2x + y    = -2

(2x + 4y = 10) - (2x + y = -2)
3y =12
y = 12/3
y = 4

x + 2y = 5
x + 2(4) = 5
x + 8 = 5
x = 5 - 8
x = -3