解方程:2x^2=3x+2;0.25X^2+2.5x-6=0;(x+2)^2=6x+7;x^2-2根号3x-6=0
问题描述:
解方程:2x^2=3x+2;0.25X^2+2.5x-6=0;(x+2)^2=6x+7;x^2-2根号3x-6=0
答
晕死 ,看教科书例题啊!!
答
2x^2=3x+22x^2-3x-2=0(2x+1)(x-2)=0x=-1/2 或 x=22x^2=3x+2x^2-3/2x-1=0x^2-3/2x+(3/4)^2-(3/4)^2-1=0(x-3/4)^2=25/16x-3/4=5/4或x-3/4=-5/4x=2或x=-1/20.25X^2+2.5x-6=0;X^2+10x-24=0(x-2)(x+12)=0x=2 或x=-120.25X...