Question

2x-y=7 x+y=5 Use elimination

Answer 1

Answer:  (x,y) = (4,1)

In other words,  x = 4 and y = 1

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Explanation:

Add the equations straight down.

• The x terms add to 3x because 2x+x = 3x
• The y terms go away when you add them since -y+y = 0y = 0
• The terms on the right hand sides add to 7+5 = 12

After those three sets of adding terms, we end up with 3x = 12. This solves to x = 4 when you divide both sides by 3.

Use this x value to find y.

2x-y = 7

2(4)-y = 7

8-y = 7

-y = 7-8

-y = -1

y = 1

or

x+y = 5

4+y = 5

y = 5-4

y = 1

Your best best is probably to use the second equation, but it doesn't hurt to have practice with both equations. Getting the same y value helps confirm we have the correct x value.

Therefore, the solution is the ordered pair (x,y) = (4,1). Meaning that x = 4 and y = 1 pair up together.

Visual confirmation can be done by using a graphing tool like Desmos. The two lines intersect at (4, 1). See below.