SOLUTION: Can someone please check to see if I sloved the following problem correctly... Question 3x + 4y + z = 7 2y + z = 3 -5x + 3y + 8z =-31 My Answer 2 = 3 - 2y 3x + 4y +

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Can someone please check to see if I sloved the following problem correctly... Question 3x + 4y + z = 7 2y + z = 3 -5x + 3y + 8z =-31 My Answer 2 = 3 - 2y 3x + 4y +      Log On


   

Question 195009: Can someone please check to see if I sloved the following problem correctly...
Question
3x + 4y + z = 7
2y + z = 3
-5x + 3y + 8z =-31
My Answer
2 = 3 - 2y
3x + 4y + 3 - 2y = 7
3x + 2y = 4
y= 4 - 3x
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2
-6 + 4y + 3 - 2y =7
2y = 10
y = 5
10 + z = 3
z = -7
-5x + 6 - 9x + 24 - 16y = -31
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2
-5x + 6 - 9x +24 - (64-48z) = -31
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2 2
-5x - 9x + 24z = -31-30+32
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2
-10x -9x + 48x= -58
29x = -58
x= -2
x=-2 y=5 z= -7
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
If you sub the 3 values for x, y and z into all 3 eqns, you'll find that it is correct.