x+3是2次3项式x²-kx-5的因式,那么k的值是多小A:8 B:-8 C:4 D:-4打错了 是 x+5是2次3项式x²-kx-5的因式,那么k的值是多小
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/27 06:36:09
![x+3是2次3项式x²-kx-5的因式,那么k的值是多小A:8 B:-8 C:4 D:-4打错了 是 x+5是2次3项式x²-kx-5的因式,那么k的值是多小](/uploads/image/z/3929298-42-8.jpg?t=x%2B3%E6%98%AF2%E6%AC%A13%E9%A1%B9%E5%BC%8Fx%26sup2%3B-kx-5%E7%9A%84%E5%9B%A0%E5%BC%8F%2C%E9%82%A3%E4%B9%88k%E7%9A%84%E5%80%BC%E6%98%AF%E5%A4%9A%E5%B0%8FA%EF%BC%9A8+B%3A-8+C%3A4+D%3A-4%E6%89%93%E9%94%99%E4%BA%86+%E6%98%AF+x%2B5%E6%98%AF2%E6%AC%A13%E9%A1%B9%E5%BC%8Fx%26sup2%3B-kx-5%E7%9A%84%E5%9B%A0%E5%BC%8F%EF%BC%8C%E9%82%A3%E4%B9%88k%E7%9A%84%E5%80%BC%E6%98%AF%E5%A4%9A%E5%B0%8F)
x)6~6cѳ5_.tOZqinvY-Og/
lZdgG6HaP%nw|gɳ/|MJB۔nMR>e.ř`qUf(
m>ٽiҧ1~OiD0!F 1u0 @+5 :Ɏ';VXOw,Zt12l[]}clfj
o 6BMZ(uv cDhu
x+3是2次3项式x²-kx-5的因式,那么k的值是多小A:8 B:-8 C:4 D:-4打错了 是 x+5是2次3项式x²-kx-5的因式,那么k的值是多小
x+3是2次3项式x²-kx-5的因式,那么k的值是多小
A:8 B:-8 C:4 D:-4
打错了 是 x+5是2次3项式x²-kx-5的因式,那么k的值是多小
x+3是2次3项式x²-kx-5的因式,那么k的值是多小A:8 B:-8 C:4 D:-4打错了 是 x+5是2次3项式x²-kx-5的因式,那么k的值是多小
将x=-5代入可得
5²+5k-5=0
5k=-20
k=-4
选D
x+3=0是x^2-kx-5=0的一个解
x=-3带入,9+3k-5=0, k=-4/3
(x+3)(x-5/3)
=x²+4/3x-5
k=-4/3