Question

x(x－3)=2x＋1用公式法解怎么解

Answer 1

x²-3x=2x+1
x²-2x-3x-1=0
x²-5x-1=0
x1=二分之五加根号29
x2=二分之五减根号29

追问

谢了

Answer 2

x²-3x=2x+1
x²-5x-1=0
x=[-（-5）±√（-5）²-4*1*（-1）]/2*1=（5±√29）/2

追问

谢了