Math CentralQuandaries & Queries


Question from Tee, a student:

2x -y =5
2x +=y =5

and also
3/7x + 5/9y =27 (fractions)

I have to find the addition method to both problems

Hi Tee,

If the first problem is to solve for x and y when

2x - y =5
2x + y =5

then you can add the two equations to obtain

4x = 10

and solve for x. In fact is is easier than that. if 2x - y is 5 and 2x + y is also 5 then y must be zero.

I don't understand the second problem. What are the instructions?


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