2x + Y = 1300
and your question is?
well, there is many ways you can do this, for example let x=630 and y=40 so the statment would read 2times 630 plus 40 = 1300
2X630+40=1300
Algebraically solve as one would with an equation of two variables. Solve for y in terms of x or solve for x in terms of y. Isolate according to which of the two procedures comes out most cleanly. Plug the expression back in and you can solve the equation thusly by substitution. Also, this easily can be thought of as being a line graph in slope/ y-intercept form y= negative 2x + 1300 or y= 1300-2x. Finally, one can approach this by intercepts (when x=0, y=?, when y=0, x=?).
To find the value of x and y in the equation 2x + y = 1300, you need to have either the value of x or y given, or have another equation involving x and y. This equation has two variables, so you need two equations to solve for both variables.
If you have another equation or the values of x or y, please provide that information so we can continue solving the system of equations.