How do you solve the problem 3X plus 5Y equals 7?

Answer 1

To solve for two unknowns (x and y) you need two independent equations.

All that you can do with the above is to express x in terms of y, as follows:

3X + 5Y = 7 => 3X = 7 - 5Y or X = (7 - 5Y)/3

or you can express y in terms of x: Y = (7 - 3X)/5