Question

2x²+3x-1＝0用配方法解

Answer 1

2x^2+3x-1=0
2x^2+3x=1
x^2+3x/2=1/2
x^2+3x/2+(3/4)^2=1/2+(3/4)^2
(x+3/4)^2=17/16
x+3/4=正负根号17/4
x=-3/4正负根号17/4
x1=3/4+根号17/4 x2=3/4-根号17/4

Answer 2

你好！2x²-5x=-3x²-5/2x=-3/2x²-5/2x+25/16=-3/2+25/16(x-5/4)²=1/16x-5/4=±1/4x₁=3/2，x₂=1-3x²-2x+1=03x²+2x=1x²+2/3x=1/3x²+2/3x+1/9=1/3+1/9(x+1/3)²=4/9x+1/3=±2/3x₁=1/3，x₂=-1