let solutions be: x, -x, y, z
x + -x + y + z = -b/a
y + z = -5/6 -----------(1)
x.-x + x.y + x.z + -x.y + -x.z + y.z = c/a
-x^2 + yz = -24/6 -----------(2)
x.-x.y.z = e/a
-x^2.y.z = 18/6 -----------(3)
solve these 3 for the 3 unknowns:
firstly, looking at (2) if we...