Question

x+y=1
2x-y=-7

Answer 1

add the 2 equations, what u get ?

Answer 2

2x=-6

Answer 3

the left side
x+2x = 3x
isn't it ?

Answer 4

i got a different answer

Answer 5

when you add the equations
for left side
x+y + 2x -y = 1-7

the y's cancel out
and what remains is x+2x on left, hich is 3x

so its
3x = -6
got this ?

Answer 6

multiply the first equation by 2 and subtract the second equation, you will get
3y=9 and thus y = 3; you can solve the rest.