初一数学因式分解~急!拜托了!急!!!
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发布时间:2022-04-26 22:37
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热心网友
时间:2022-06-19 04:31
1.
2.
x^2-xy-2y^2-x-y =(x-2y)(x+y)-(x+y)
=(x-2y-1)(x+y)
x^3+2x^2-5x-6 =x^3+x^2+x^2+x-6x-6
=x^2(x+1)+x(x+1)-6(x+1)
=(x^2+x-6)(x+1)
=(x-2)(x+3)(x+1)
a^2-6ab+9b^2-4a+12b+4
=(a-3b)^2-4(a-3b)+4
=(a-3b-2)^2
x^2+2xy+y^2-x-y+1/4
=(x+y)^2-(x+y)+1/4
=(x+y-1/2)^2
a^2-10ab+25b^2-5a+25b-6
=(a-5b)^2-5(a-5b)-6
=(a-5b-6)(a-5b+1)
3,C
4,B
热心网友
时间:2022-06-19 04:31
1.
2.
x^2-xy-2y^2-x-y =(x-2y)(x+y)-(x+y)
=(x-2y-1)(x+y)
x^3+2x^2-5x-6 =x^3+x^2+x^2+x-6x-6
=x^2(x+1)+x(x+1)-6(x+1)
=(x^2+x-6)(x+1)
=(x-2)(x+3)(x+1)
a^2-6ab+9b^2-4a+12b+4
=(a-3b)^2-4(a-3b)+4
=(a-3b-2)^2
x^2+2xy+y^2-x-y+1/4
=(x+y)^2-(x+y)+1/4
=(x+y-1/2)^2
a^2-10ab+25b^2-5a+25b-6
=(a-5b)^2-5(a-5b)-6
=(a-5b-6)(a-5b+1)
3,C
4,B