SOLUTION: how do i work out this simultaneous equation? 2x-y=4 2y+x=7

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Question 25073: how do i work out this simultaneous equation?

2x-y=4
2y+x=7
Answer by Earlsdon(6103) About Me  (Show Source):
You can put this solution on YOUR website!
Solve: You can use "substitution" to solve this.
1) 2x-y+=+4 Rewrite as: y+=+2x-4 and substitute into equation 2)
2) 2y%2Bx+=+7
3) 2%282x-4%29%2Bx+=+7 Simplify and solve for x.
4x-8%2Bx+=+7
5x-8+=+7 Add 8 to both sides of the equation.
5x+=+15 Divide both sides by 5.
x+=+3 Now substitute this into the rewrite of equation 1) to find y.
y+=+2%283%29-4
y+=+6-4
y+=+2
Solution is: (3, 2)
Check:
Equation 1)
2%283%29-2+=+4
6-2+=+4
4+=+4
Equation 2)
2%282%29%2B3+=+7
4%2B3+=+7
7+=+7