解方程:x²+6x=2x+12 2x²-3x-1=0 亲们会写的帮帮忙咯.
问题描述:
解方程:x²+6x=2x+12 2x²-3x-1=0 亲们会写的帮帮忙咯.
答
x²+6x=2x+12
X²+4X-12=0
﹙X-2﹚﹙X+6﹚=0
X-2=0或X+6=0
x=2或x=﹣6
2x²-3x-1=0
x²-3/2x=1/2
(x-3/4﹚²=17/16
x-3/4=±√17/4
X=﹙3±√17﹚/4