Question 122998
First of all, I assume since the question involves two linear equation that you are looking for the values of x and y.

*[invoke linear_substitution "x", "y", 3, 1, 0, 4, 1, 2]

In other words, in you plug in -3x for y in the equation 4x + y = 2. The answer would come up as x=2. You then have to plug in 2 for x, which will yield y = 6.

The solution is (2,-6)