151k views
3 votes
Using elimationmethod 2x +y=10, 2x - y = 9



1 Answer

3 votes

Answer:

x = 19/4, y = 1/2

Explanation:

To solve using the elimination method, first set the two equations out like this:
2x + y = 10

2x - y = 9

Now subtract the bottom equation from the first one, going through each term separately.

2x - (2x) + y - (-y) = 10 - (9)

∴ 2y = 1

y = 1/2

As you can see, this method works well when either the x value or y value in both equations are the same, as this leads to one of them cancelling out (the x in this case) leaving only the y. Now we simply substitute this y value back into one of the original two equations to find x. Hence:

2x + y = 10

2x + 1/2 = 10

2x = 19/2

x = 19/4

Hope that helps!

User Drcocoa
by
7.4k points