数学三次一元方程和四次一元方程解答
3个回答

X^4+7X²+12=0

(x²+3)(x²+4)=0

x1=√3i,x2=-√3i,x3=2i,x4=-2i

X^6-7X³-8=0

(x³-8)(x³+1)=0

x1=-1,x2=2

X³+12=3X²+4X

x³-4x=3x²-12

x(x+2)(x-2)=3(x+2)(x-2)

(x-3)(x-2)(x+2)=0

x1=3,x2=2,x3=-2

X³- 5.3X²+1.46X+0.2=0

x³-5x²-0.3x²+1.5x-0.04x+0.2=0

x²(x-5)-0.3x(x-5)-0.04(x-5)=0

(x²-0.3x-0.04)(x-5)=0

(x+0.1)(x-0.4)(x-5)=0

x1=-0.1,x2=0.4,x3=5