若x^2+2x-3=0,则3x^2+6x-1

问题描述:

若x^2+2x-3=0,则3x^2+6x-1
RT

3x^2+6x-1 =3x^2+6x+9-9-1=(3x^2+6x+9)-9-1 =3(x^2+2x-3)-10=-10