SOLUTION: x + y = 7 x + 3y = 11

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Question 227843: x + y = 7
x + 3y = 11
Answer by drj(1380) About Me  (Show Source):
You can put this solution on YOUR website!
x+%2B+y+=+7 Equation A
x+%2B+3y+=+11 Equation B

Step 1. Subtract Equation A from Equation B (or Equation B - Equation A) to eliminate x

x-x%2B3y-y=11-7

2y=4

Step 2. Divide by 2 to both sides of the equation

2y%2F2=4%2F2

y=2

Step 3. Now Substitute y=2 into equation A x+%2B+y+=+7 to find x

x%2B2=7

Subtract 2 from both sides to get x.

x%2B2-2=7-2

x=5

Step 4. Now we have x=5 and y=2 as a solution. Check to see if this also satisfies equation B x+%2B+3y+=+11.

5%2B3%2A2=11

11=11 which is a true statement

Step 5. ANSWER: The solution is x=5 and y=2. Or the intersection point between these two lines is (5,2). See graph below,

graph%28400%2C400%2C+-10%2C+10%2C+-10%2C+10%2C+-x%2B7%2C+-x%2F3%2B11%2F3%29

I hope the above steps were helpful.

For free Step-By-Step Videos on Introduction to Algebra, please visit http://www.FreedomUniversity.TV/courses/IntroAlgebra or for Trigonometry visit http://www.FreedomUniversity.TV/courses/Trigonometry.

And good luck in your studies!

Respectfully,
Dr J

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