Question

2x+y=-1
-4x+6y=6

solve with substitution and elimination, show work please.

Answer 1

can anyone help?

Answer 2

2x+y=-1 ...................... (1)
-4x+6y=6 ...................... (2)

from (1) y = -1 -2x we substitute it in (2) we get

-4x + 6( -1 -2x ) = 6
-4x -6 -12x = 6
-16x = 12
-8x = 6
-4x = 3
x = -3/4
x = -0.75

Answer 3

Substitution:
Rewrite the top equation as
y=-1-2x
and plug into the bottom equation:
-4x + 6(-1-2x)=6
-4x -6 - 12x = 6
-16x = 12
x = 12/-16
x = - 3/4
plug this into one of the original equations
y = -1-2(-3/4)
y = -4/4 + 6/4
y = 2/4
y = 1/2

Elimination:
It will be easier to multiply the top equation by 2
4x+2y=-2
Then add the second equation
4x - 4x + 2y + 6y = -2 + 6
8y = 4
y = 4/8 = 1/2
Plug this into one of the original equations:
2x + (1/2) = -1
2x = -2/2-1/2
2x = - 3/2
x = (-3/2)/2
x=-3/4

Answer 4

S0fw0N, y should be positive.