2x⁴-x²-3=0
2x⁴+2x²-3x²-3=0
2x²(x²+1)-3(x²+1)=0
(2x²-3)(x²+1)=0
2x²-3=0
2x²=3
x²=3/2
x=-√(3/2) ∨ x=√(3/2)
|-√(3/2)|+|√(3/2)|=√(3/2)+√(3/2)=2√(3/2)
2x⁴-x²-3=0
2x⁴+2x²-3x²-3=0
2x²(x²+1)-3(x²+1)=0
(2x²-3)(x²+1)=0
2x²-3=0
2x²=3
x²=3/2
x=-√(3/2) ∨ x=√(3/2)
|-√(3/2)|+|√(3/2)|=√(3/2)+√(3/2)=2√(3/2)