SOLUTION: Solve with elimination, explain each step given. 2a + 3b - 5c = -5 -2a - 2b - c = -14 4a - 4b + 4c = -4

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Question 1091823: Solve with elimination, explain each step given.
2a + 3b - 5c = -5
-2a - 2b - c = -14
4a - 4b + 4c = -4
Found 2 solutions by Fombitz, MathTherapy:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Add R%5B1%5D and R%5B2%5D to eliminate a,
2a%2B3b-5c-2a-2b-c=-5-14
R%5B4%5D:b-6c=-19
Multiply R%5B1%5D by R%5B2%5D and subtract from R%5B3%5D to eliminate a,
4a-4b%2B4c-4a-6b%2B10c=-4%2B10
R%5B5%5D:-10b%2B14c=6
Multiply R%5B4%5D by 10 and add to R%5B5%5D to eliminate b.
10b-60c-10b%2B14c=-190%2B6
-46c=-184
c=%28-184%29%2F%28-46%29
Solve for c then work backwards to solve for b and then a.

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Solve with elimination, explain each step given.
2a + 3b - 5c = -5
-2a - 2b - c = -14
4a - 4b + 4c = -4
2a + 3b - 5c = - 5 -------- eq (i) 
- 2a - 2b - c = - 14 ------ eq (ii)
4a - 4b + 4c = - 4 -------- eq (iii)
b - 6c = - 19 ---------- Adding eqs (i) & (ii) ------ eq (iv)
2a - 2b + 2c = - 2 ----- Dividing eq (iii) by 2 ----- eq (v)
- 4b +   c = - 16 ------ Adding eqs (v) & (ii) ------ eq (vi)
  4b - 24c = - 76 ------ Multiplying eq (iv) by 4 --- eq (vii)
- 23c = - 92


- 4b + 4 = - 16 ------- Substituting 4 for c in eq (vi)
- 4b = - 16 - 4
- 4b = - 20


- 2a - 2(5) - 4 = - 14 ------- Substituting 5 for b, and 4 for c in eq (ii)
- 2a - 10 - 4 = - 14
- 2a = 0
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