Question

解下列方程.1.2（x+3)²=x(x+3) 2.x²2根号5x+2=0

Answer 1

2（x+3)²=x(x+3)

2(x+3)²-x(x+3)=0

(x+3)(2x+6-x)=0

(x+3)(x+6)=0

x1=-3,x2=-6

2.x²-2根号5x+2=0

判别式=20-8=12

x=(2√5±2√3)/2=√5±√3