Question 1007830
I need to solve this equation using substitution
-x-y-z=-8
-4x+4y+5z=7
2x+2z=4
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It's not just an equation.  It's 3 equations, a system of equations.
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-x-y-z=-8
-4x+4y+5z=7
2x+2z=4 --> x + z = 2 --> z = 2 - x
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Sub for z in the 1st 2 equations.
-x-y- (2-x) = -8
-x-y -2+x = -8
-y-2 = -8
y = 6
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-4x+4y+5z=7
Sub for y & z
-4x + 4*6 + 5(2-x) = 7
-4x + 24 + 10 - 2x = 7
-6x = -27
x = 9/2
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z = 2 - x
x = -5/2
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