I assume that you want to find an x and a y that solves the two equations.
You can solve one equation for y and then substitute what y equals into the second evuation to get a value for x. Then take the x value and sub into an original equation to find the y value.
If you are familiar with linear algebra, you can build an array of the coeficients then use Solve Linear Equations.vi . It is found in LabVIEW Full and Pro.