夺冠之路 提公因式法1.若x+y=5,xy=-50,则x²y+xy²=?(过程)2.先分解因式,再求值:(1)(x+2)(x-3)(x²-7)+(2+x)(3-x)(x+3) 其中x=5(2)a(b-1)+c(1-b)-b+1其中a=1,b=2,c=33.计算(-2)^100+(-2)^101=?4.猜一猜81^
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![夺冠之路 提公因式法1.若x+y=5,xy=-50,则x²y+xy²=?(过程)2.先分解因式,再求值:(1)(x+2)(x-3)(x²-7)+(2+x)(3-x)(x+3) 其中x=5(2)a(b-1)+c(1-b)-b+1其中a=1,b=2,c=33.计算(-2)^100+(-2)^101=?4.猜一猜81^](/uploads/image/z/1973096-8-6.jpg?t=%E5%A4%BA%E5%86%A0%E4%B9%8B%E8%B7%AF+%E6%8F%90%E5%85%AC%E5%9B%A0%E5%BC%8F%E6%B3%951.%E8%8B%A5x%2By%3D5%2Cxy%3D-50%2C%E5%88%99x%26sup2%3By%2Bxy%26sup2%3B%3D%3F%EF%BC%88%E8%BF%87%E7%A8%8B%EF%BC%892.%E5%85%88%E5%88%86%E8%A7%A3%E5%9B%A0%E5%BC%8F%2C%E5%86%8D%E6%B1%82%E5%80%BC%EF%BC%9A%EF%BC%881%EF%BC%89%28x%2B2%29%28x-3%29%28x%26sup2%3B-7%29%2B%282%2Bx%29%283-x%29%28x%2B3%29+%E5%85%B6%E4%B8%ADx%3D5%EF%BC%882%EF%BC%89a%28b-1%29%2Bc%281-b%29-b%2B1%E5%85%B6%E4%B8%ADa%3D1%2Cb%3D2%2Cc%3D33.%E8%AE%A1%E7%AE%97%EF%BC%88-2%EF%BC%89%5E100%2B%28-2%29%5E101%3D%3F4.%E7%8C%9C%E4%B8%80%E7%8C%9C81%5E)
夺冠之路 提公因式法1.若x+y=5,xy=-50,则x²y+xy²=?(过程)2.先分解因式,再求值:(1)(x+2)(x-3)(x²-7)+(2+x)(3-x)(x+3) 其中x=5(2)a(b-1)+c(1-b)-b+1其中a=1,b=2,c=33.计算(-2)^100+(-2)^101=?4.猜一猜81^
夺冠之路 提公因式法
1.若x+y=5,xy=-50,则x²y+xy²=?
(过程)2.先分解因式,再求值:(1)(x+2)(x-3)(x²-7)+(2+x)(3-x)(x+3) 其中x=5
(2)a(b-1)+c(1-b)-b+1其中a=1,b=2,c=3
3.计算(-2)^100+(-2)^101=?
4.猜一猜81^7-27^9-9^13能被45整除吗?说明理由
夺冠之路 提公因式法1.若x+y=5,xy=-50,则x²y+xy²=?(过程)2.先分解因式,再求值:(1)(x+2)(x-3)(x²-7)+(2+x)(3-x)(x+3) 其中x=5(2)a(b-1)+c(1-b)-b+1其中a=1,b=2,c=33.计算(-2)^100+(-2)^101=?4.猜一猜81^
1.x²y+xy²=xy(x+y)=-50*5=-250
2.(x+2)(x-3)(x²-7)+(2+x)(3-x)(x+3)
=(x+2)(x-3)(x²-7)-(2+x)(x-3)(x+3)
=(x+2)(x-3)[(x²-7)-(x+3)]
=(x+2)(x-3)(x²-x-10)
=7*2*10
=140
a(b-1)+c(1-b)-b+1
=a(b-1)-c(b-1)-(b-1)
=(a-c-1)(b-1)
=-3*1
=-3
3.(-2)^100+(-2)^101
=(-2)^100(1+(-2))
=2^100*(-1)
=-(2^100)
4.81^7-27^9-9^13
=3^28-3^27-3^26
=3^26(9-3-1)
=3^26*5
=3^24*45
可以~
1、.....=xy(x+y)=-50×5=-250
2、(1).....=(x+2)(x-3)(x²-7)-(x+2)(x-3)(x+3)=(x+2)(x-3)[(x²-7)-(x+3)]=7×2×(18-8)=140
(2).....=a(b-1)-c(b-1)-b+1=(a-c)-(b-1)-b+1 后面的自己代进去算
1, x²y+xy²=xy(x+y)=-50*5=-250
2, (1) (x+2)(x-3)(x²-7)+(2+x)(3-x)(x+3)
=(x+2)(x-3)[(x^2-7)-(x+3)]
=(x+2)(x-3)(x^2-x-10)
当 =x=5时,
...
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1, x²y+xy²=xy(x+y)=-50*5=-250
2, (1) (x+2)(x-3)(x²-7)+(2+x)(3-x)(x+3)
=(x+2)(x-3)[(x^2-7)-(x+3)]
=(x+2)(x-3)(x^2-x-10)
当 =x=5时,
原式=7*2*(25-5-10)
=140
(2) a(b-1)+c(1-b)-b+1
=a(b-1)-c(b-1)-(b-1)
=(b-1)(a-c-1)
当a=1,b=2,c=3时,
原式=-3
3, (-2)^100+(-2)^101=2^100-2*2^100= -2^100
4, 81^7-27^9-9^13=[(3^4)^7]-[(3^3)^9]-[(3^2)^13]
=3^28-3^27-3^26
=3*3^27-3^27-3^26
=2*3^27-3^26
=6*3^26-3^26
=5*3^26
所以81^7-27^9-9^13能被45整除。
收起
1,、xy(x+y)=5*50=250
2、(1)原式=(x+2)(x-3)(x²-7-x-3)=(x+2)(x-3)(x²-x-10)=7*2*(25-5-10)=140