The modulus function will give us foru combinations:

for 3x-2y+10 > 0 we get |3x-2y+10| = 3x-2y+10

for 3x-2y+10 < 0 we get |3x-2y+10| = -3x+2y-10

for 2x-3y > 0 we get |2x-3y| = 2x-3y and

for 2x-3y < 0 we get |2x-3y| = -2x+3y

Using these for cases we get for four relations

x = y; x = -y; x+y = -20 and x-y = -4

We have to now use these in first equation to get the value. Remember we do not have a definite method to solve a bi-quadratic equation.