SOLUTION: Solve the equation a + b + c = 5 4a + 2b + c = 11 9a + 3b + c = -3

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Question 54491: Solve the equation
a + b + c = 5
4a + 2b + c = 11
9a + 3b + c = -3
Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
-a - b - c = -5
4a + 2b + c = 11
~> 3a + b = 6 or as: b = 6 - 3a
4a + 2b + c = 11
-9a - 3b - c = 3
~> -5a - b = 14
Plug:
-5a - (6 - 3a) = 14
-5a - 6 + 3a = 14
-2a = 20
a = -10
Plug:
b = 6 - 3a
b = 6 + 30 = 36
Plug:
a + b + c = 5
-10 + 36 + c = 5
c = -21