SOLUTION: `6x+2y=8 -3x+y=20

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Question 214739: `6x+2y=8
-3x+y=20
Answer by drj(1380) About Me  (Show Source):
You can put this solution on YOUR website!
6x%2B2y=8 Equation A
-3x%2By=20 Equation B

Step 1. Multiply Equation B by 2 and Add the two equations.

-3x%2By=20
-6x%2B2y=40
6x%2B2y=8
Step 2. This yields

4y=48 or y=12

Step 3. Substitue y=12 into equation A or B. Here's for Equation A

6x%2B2%2A12=8

6x=-16

x=-16%2F6=-8%2F3

Step 4. ANSWER: The solution is x=-8/3 and y=12.

As a check here's the solution using SUBSTITUTION:

Solved by pluggable solver: SOLVE linear system by SUBSTITUTION
Solve:
+system%28+%0D%0A++++6%5Cx+%2B+2%5Cy+=+8%2C%0D%0A++++-3%5Cx+%2B+1%5Cy+=+20+%29%0D%0A++We'll use substitution. After moving 2*y to the right, we get:
6%2Ax+=+8+-+2%2Ay, or x+=+8%2F6+-+2%2Ay%2F6. Substitute that
into another equation:
-3%2A%288%2F6+-+2%2Ay%2F6%29+%2B+1%5Cy+=+20 and simplify: So, we know that y=12. Since x+=+8%2F6+-+2%2Ay%2F6, x=-2.66666666666667.

Answer: system%28+x=-2.66666666666667%2C+y=12+%29.



The results are the same as before.

I hope the above steps were helpful.

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And good luck in your studies!

Respectfully,
Dr J