# Solve for x and y: 2x-y=5

justaguide | College Teacher | (Level 2) Distinguished Educator

Posted on

There is only equation given: 2x - y = 5. There are two independent variables x and y.

To determine a unique value for n independent variables it is essential to have n independent equations containing them.

As that is not the case here we can only evaluate the value of x or y in terms of the other variable which can take on an infinite number of values.

It is not possible to solve for x and y if only the equation 2x - y = 5 is given.

michaelcoffey | College Teacher | eNotes Newbie

Posted on

2x-y=5 (original)

2x-5=y (rewritten to isolate the "y" to one side of the equation)

y=2x-5 (slope intercept)

Write a table which substitutes values of -1, 0, and 1 for "x". This will allow you to solve for y. Plug in the numbers you wrote where there is "x". I will use "0" as the example.

y=2(0)-5

y=0-5

y= -5

the only way to slove this is to write it in slope intercept and then build a table. Unless, that is, you have been given "y" or "x" values.