SOLUTION: 3x-4y=27 2x+6y=-34 Solve by elimination method

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Question 1128185: 3x-4y=27
2x+6y=-34
Solve by elimination method
Found 2 solutions by MathLover1, MathTherapy:
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

3x-4y=27......eq.1
2x%2B6y=-34.....eq.2
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Solve by elimination method
3x-4y=27......eq.1...both sides multiply by 2
2x%2B6y=-34.....eq.2...both sides multiply by 3
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6x-8y=54......eq.1
6x%2B18y=-102.....eq.2
----------------------------------substitute eq.2 from eq.1

6x-8y-%286x%2B18y%29=54-%28-102%29
cross%286x%29-8y-cross%286x%29-18y=54%2B102
-8y-18y=156
-26y=156
y=156%2F-26
y=-6

go to
3x-4y=27......eq.1, substitute y
3x-4%28-6%29=27
3x%2B24=27
3x=27-24
3x=3
x=1



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

3x-4y=27
2x+6y=-34
Solve by elimination method
3x - 4y = 27 ------- eq (i)

2x + 6y = - 34_____2(x + 3y) = 2(- 17)______x + 3y = - 17 ------ eq (ii)

- 3x - 9y = 51 ----- Multiplying eq (ii) by - 3 ----- eq (iii)

- 13y = 78 --------- Adding eqs (iii) & (i)

highlight_green%28matrix%281%2C5%2C+y%2C+%22=%22%2C+78%2F%28-+13%29%2C+%22=%22%2C+-+6%29%29  



3x - 4(- 6) = 27 ------ Substituting - 6 for y in eq (i)

3x + 24 = 27

3x = 3

highlight_green%28matrix%281%2C5%2C+x%2C+%22=%22%2C+3%2F3%2C+%22=%22%2C+1%29%29