不解方程,求下列方程两根之和与两根之积:
(1)4x2+1=7x,x1+x2=______,x1?x2=______.
(2)3x2-1=0,x1+x2=______,x1?x2=______.
(3)x2-6x=0,x1+x2=______,x1?x2=______.
(4)2x2-(m+1)x-m=0,x1+x2=______,x1?x2=______.
网友回答
解:(1)先把方程化为:4x2-7x+1=0,∴x1+x2=,x1?x2=,
(2)根据根与系数的关系得:x1+x2=0,x1?x2=-.
(3)根据根与系数的关系得:x1+x2=6,x1?x2=0.
(4)根据根与系数的关系得:x1+x2=,x1?x2=.
故