Question

解方程： x的二次方-2+1=9x的二次方+6x+1

Answer 1

x^2-2x+1=9x^2+6x+1

(x-1)^2=(3x+1)^2

(x-1)^2-(3x+1)^2=0

[(x-1)-(3x+1)][(x-1)+(3x+1)]=0

(-2x-2)*4x=0

x(x+1)=0

x=0或x=-1