1.已知多项式x²+kx+18 可以在整数范围内因式分解,求k的可能的值.(尽量有过程)2.已知:ax²+2x+3=a(x-p)(x-3),求a的值.3.若(x²+y²)(x²+y²-2)+1=0求x²+y²的值
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![1.已知多项式x²+kx+18 可以在整数范围内因式分解,求k的可能的值.(尽量有过程)2.已知:ax²+2x+3=a(x-p)(x-3),求a的值.3.若(x²+y²)(x²+y²-2)+1=0求x²+y²的值](/uploads/image/z/7041251-11-1.jpg?t=1.%E5%B7%B2%E7%9F%A5%E5%A4%9A%E9%A1%B9%E5%BC%8Fx%26sup2%3B%2Bkx%2B18+%E5%8F%AF%E4%BB%A5%E5%9C%A8%E6%95%B4%E6%95%B0%E8%8C%83%E5%9B%B4%E5%86%85%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%2C%E6%B1%82k%E7%9A%84%E5%8F%AF%E8%83%BD%E7%9A%84%E5%80%BC.%EF%BC%88%E5%B0%BD%E9%87%8F%E6%9C%89%E8%BF%87%E7%A8%8B%EF%BC%892.%E5%B7%B2%E7%9F%A5%EF%BC%9Aax%26sup2%3B%2B2x%2B3%3Da%EF%BC%88x-p%EF%BC%89%EF%BC%88x-3%EF%BC%89%2C%E6%B1%82a%E7%9A%84%E5%80%BC.3.%E8%8B%A5%EF%BC%88x%26sup2%3B%2By%26sup2%3B%EF%BC%89%EF%BC%88x%26sup2%3B%2By%26sup2%3B-2%EF%BC%89%2B1%3D0%E6%B1%82x%26sup2%3B%2By%26sup2%3B%E7%9A%84%E5%80%BC)
1.已知多项式x²+kx+18 可以在整数范围内因式分解,求k的可能的值.(尽量有过程)2.已知:ax²+2x+3=a(x-p)(x-3),求a的值.3.若(x²+y²)(x²+y²-2)+1=0求x²+y²的值
1.已知多项式x²+kx+18 可以在整数范围内因式分解,求k的可能的值.(尽量有过程)
2.已知:ax²+2x+3=a(x-p)(x-3),求a的值.
3.若(x²+y²)(x²+y²-2)+1=0
求x²+y²的值
1.已知多项式x²+kx+18 可以在整数范围内因式分解,求k的可能的值.(尽量有过程)2.已知:ax²+2x+3=a(x-p)(x-3),求a的值.3.若(x²+y²)(x²+y²-2)+1=0求x²+y²的值
1、按照十字相乘法
18可分解为1*18或-1*-18;2*9或-2*-9;3*6或-3*-6
k=1+18=19或-1-18=-19或2+9=11或-2-9=-11或3+6=9或-3-6=-9
2、ax²+2x+3=a(x-p)(x-3)=a(x²-3x-px+3p)=ax²-3ax-apx+3ap
-3a-ap=2
3ap=3 ---->ap=1
-3a-1=2
-3a=3
a=-1
3、(x²+y²)(x²+y²-2)+1=0
设x²+y²=a,则
原式=a(a-2)+1=a²-2a+1=(a-1)²=0
a-1=0
a=1
x²+y²=a=1
1.K=9,11,19,-9,-11,-19
2.ax²+2x+3=a(x-p)(x-3)
ax²+2x+3=ax²-(3+p)ax+3ap
2x+3=-(3+p)ax+3ap
∴2=-3a-ap 且3ap=3 ∴ap=1代如前面一个式子
得a=-1
3.令x²+y²=t≥0
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1.K=9,11,19,-9,-11,-19
2.ax²+2x+3=a(x-p)(x-3)
ax²+2x+3=ax²-(3+p)ax+3ap
2x+3=-(3+p)ax+3ap
∴2=-3a-ap 且3ap=3 ∴ap=1代如前面一个式子
得a=-1
3.令x²+y²=t≥0
则(x²+y²)(x²+y²-2)+1=0
为t(t-2)+1=0
t²-2t+1=0
(t-1)²=0
t=1
∴x²+y²=1
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i don't know