SOLUTION: how do I solve x+3y=6 and 2x+3y=18 by the substitution method

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Question 928038: how do I solve x+3y=6 and 2x+3y=18 by the substitution method
Found 2 solutions by TimothyLamb, MathTherapy:
Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
x+3y=6
2x+3y=18
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put the system of linear equations into standard form
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x+3y=6
2x+3y=18
---
copy and paste the above standard form linear equations in to this solver:
https://sooeet.com/math/system-of-linear-equations-solver.php
---
solution:
x = 12
y = -2
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by substitution:
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x + 3y = 6
x = 6 - 3y
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2(6 - 3y) + 3y = 18
12 - 6y + 3y = 18
-3y = 6
y = -2
---
x = 6 - 3y
x = 6 - 3*(-2)
x = 12
---
solution by substitution:
x = 12
y = -2
---
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Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

how do I solve x+3y=6 and 2x+3y=18 by the substitution method
  

 x + 3y =  6_______x = 6 - 3y ------- eq (i)

2x + 3y = 18 ------ eq (ii)

2(6 - 3y) + 3y = 18 ------- Substituting 6 - 3y for x in eq (ii)

12 - 6y + 3y = 18

- 6y + 3y = 18 - 12

- 3y = 6

y+=+6%2F%28-+3%29, or highlight_green%28-+2%29



x + 3(- 2) = 6 ------ Substituting - 2 for y in eq (i)

x - 6 = 6

x = 6 + 6, or highlight_green%28x+=+12%29       

You can do the check!! 

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