若 x平方 + 3x - 1 = 0, 则 x三次方 + 5x平方 + 5x + 18 = ?
麻烦说出过程,谢谢!
人气:421 ℃ 时间:2019-09-23 08:55:02
解答
x^2+3x=1
x^3+5x^2+5x+18
=x^3+3x^2+2x^2+5x+18
=x(x^2+3x)+2x^2+5x+18
=x*1+2x^2+5x+18
=2x^2+6x+18
=2(x^2+3x)+18
=2*1+18
=20
推荐
猜你喜欢
- 平面内有7个点,其中有5个点在一条直线上,此外无三点共线,经过这7个点可连成不同直线的条数是_.
- u will find someone who really care about u,中文翻译
- 词语接龙大全,20个
- we wash our faces and brush our t___every morning
- 一道数学题需详解
- 小学五年级下册数学期末试卷
- I don't know she can swim,can she的肯定回答
- 设全集U={1,2,3,4,5},A={ 2,5},求CuA的真子集的个数