问题
填空题
已知x2+x-3=0,则代数式x3+2x2-2x+2值为______.
答案
∵x2+x-3=0,∴x2+x=3,
x3+2x2-2x+2,
=x(x2+x)+x2-2x+2,
=3x+x2-2x+2,
=x2+x+2,
当x2+x=3时,原式=3+2=5.
故答案为:5.
已知x2+x-3=0,则代数式x3+2x2-2x+2值为______.
∵x2+x-3=0,∴x2+x=3,
x3+2x2-2x+2,
=x(x2+x)+x2-2x+2,
=3x+x2-2x+2,
=x2+x+2,
当x2+x=3时,原式=3+2=5.
故答案为:5.