SOLUTION: y=-4x-8 -8x+4y=-8 Please show step by step work, so I can see if the answer I have is correct.

Algebra ->  Systems-of-equations -> SOLUTION: y=-4x-8 -8x+4y=-8 Please show step by step work, so I can see if the answer I have is correct.      Log On


   



Question 1023527: y=-4x-8
-8x+4y=-8
Please show step by step work, so I can see if the answer I have is correct.

Found 3 solutions by josgarithmetic, ikleyn, MathTherapy:
Answer by josgarithmetic(39631) About Me  (Show Source):
You can put this solution on YOUR website!
Check the set of equations USING the x and y which you found and see if both equations are satisfied.










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-8x+4(-8-4x)=-8
-8x-32-4x=-8
-12x-32=-8
12x+32=8
12x=8-32
12x=-24
x=-2
Now you find y.

Answer by ikleyn(52925) About Me  (Show Source):
You can put this solution on YOUR website!
.
y=-4x-8
-8x+4y=-8
Please show step by step work, so I can see if the answer I have is correct.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

y = -4x - 8      (1)
-8x + 4y = -8    (2)

You just have y expressed via x in equation (1).
So, simply substitute it into equation (2). You will get a single equation for x:

-8*x + 4*(-4x - 8) = -8.

Simplify and solve it:

-8x - 16x - 32 = -8,

-24x = -8 + 32,
-24x = 24,

x = 24%2F%28-24%29 = -1.

Now from (1) y = -4x - 8 = -4*(-1) - 8 = 4 -8 = -4.

Answer. x = -1, y = -4.


Answer by MathTherapy(10558) About Me  (Show Source):
You can put this solution on YOUR website!

y=-4x-8
-8x+4y=-8
Please show step by step work, so I can see if the answer I have is correct.
You didn't show your work, or reveal your answers. 
For that reason, I won't show mine either but I'll tell you this much: highlight_green%28matrix%281%2C3%2C+x+=+-+1%2C+when%2C+y+=+-4%29%29