用公式法解下列方程快快3x²-6x-2=0x²+4x+8=4x+11x(2x-4)=5-8x
2个回答

3x²-6x-2=0

x1=(6+(36+24)^0.5)/(2*3)

=(6+60^0.5)/6

=(6+2*(15^0.5))/6

=(3+(15^0.5))/3

=1+(5/3)^0.6

x2=(6-(36+24)^0.5)/(2*3)

=(6-60^0.5)/6

=(6-2*(15^0.5))/6

=(3-(15^0.5))/3

=1-(5/3)^0.6

x²+4x+8=4x+11

x²+8=11

x²=3

x1=(3^0.5)

x2=-(3^0.5)

x(2x-4)=5-8x

2x²-4x=5-8x

2x²+4x-5=0

x1=(-4+(16+40)^0.5)/(2*2)

=(-4+56^0.5)/4

=-1+(7/2)^0.5

x2=(-4-(16+40)^0.5)/(2*2)

=(-4-56^0.5)/4

=-1-(7/2)^0.5