解一元二次方程:5x²-8x=-1
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/04 00:07:48
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解一元二次方程:5x²-8x=-1
解一元二次方程:5x²-8x=-1
解一元二次方程:5x²-8x=-1
5x²-8x+1=0
x²-8/5x+1/5=0
x²-8/5x+(16/25)-(16/25)+1/5=0
(x-4/5)²-11/25=0
(x-4/5)²=11/25
x-4/5=±1/5*根号11
x1=4/5+1/5*根号11
x2=4/5-1/5*根号11
5x²-8x=-1
5x²-8x+1=0
a=5 b=-8 c=1
代入求根公式得
x=[8±√(64-20)]/10=(4±√11]/5
所以
x1=(4+√11]/5 x1=(4-√11]/5