SOLUTION: 2x+3y=-3 x+2y=2 This is the problem and my daughters teacher gave her this: -2R1+R2 Please explain how this is done

Algebra ->  Matrices-and-determiminant -> SOLUTION: 2x+3y=-3 x+2y=2 This is the problem and my daughters teacher gave her this: -2R1+R2 Please explain how this is done      Log On


   

Question 213891: 2x+3y=-3
x+2y=2
This is the problem and my daughters teacher gave her this: -2R1+R2
Please explain how this is done
Answer by drj(1380) About Me  (Show Source):
You can put this solution on YOUR website!
2x+3y=-3
x+2y=2

The following solves the system of linear equations by substitution.

Solved by pluggable solver: SOLVE linear system by SUBSTITUTION
Solve:
+system%28+%0D%0A++++2%5Cx+%2B+3%5Cy+=+-3%2C%0D%0A++++1%5Cx+%2B+2%5Cy+=+2+%29%0D%0A++We'll use substitution. After moving 3*y to the right, we get:
2%2Ax+=+-3+-+3%2Ay, or x+=+-3%2F2+-+3%2Ay%2F2. Substitute that
into another equation:
1%2A%28-3%2F2+-+3%2Ay%2F2%29+%2B+2%5Cy+=+2 and simplify: So, we know that y=7. Since x+=+-3%2F2+-+3%2Ay%2F2, x=-12.

Answer: system%28+x=-12%2C+y=7+%29.



I hope the above steps were helpful and I don't understand the statement: -2R1+R2

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