分解因式紧急20[标签：分解因式,]□寂寞边境□离问题结束还有15天0小时1.3ab^2-3a^2b2.-9ab+18a^2b^2-27a^3b^33.1/4-1/9x^24.9(x-y)^2-4(x-y)^25.5(x-y)^3+10(y-x)^26.4x^2-20xy+25y^27.-x^2+4xy-6y^28.(a+b)^2+10c(a+b)+25c9.(a-2

Question

分解因式
紧急 20 [ 标签：分解因式,] □寂寞边境□ 离问题结束还有15天0小时
1.3ab^2-3a^2b
2.-9ab+18a^2b^2-27a^3b^3
3.1/4-1/9x^2
4.9(x-y)^2-4(x-y)^2
5.5(x-y)^3+10(y-x)^2
6.4x^2-20xy+25y^2
7.-x^2+4xy-6y^2
8.(a+b)^2+10c(a+b)+25c
9.(a-2)^2+4(a-2)+4
10.(2^2+y^2)^2-4x^2y^2
11.1-4a^2-9b^2+12ab

Answer 1

1.3ab^2-3a^2b=3ab(b-a)
2.-9ab+18a^2b^2-27a^3b^3=-9ab(1-2ab+3a^2b^2)
3.1/4-1/9x^2=(1/2-1/3x)(1/2+1/3x)
4.9(x-y)^2-4(x-y)^2=5(x-y)^2
5.5(x-y)^3+10(y-x)^2=5(x-y)^2(x-y-2)
6.4x^2-20xy+25y^2=(2x-5y)^2
7.-x^2+4xy-6y^2=-(x^2-4xy+6y^2)
8.(a+b)^2+10c(a+b)+25c^2=(a+b+5c)^2
9.(a-2)^2+4(a-2)+4=(a-2+2)^2=a^2
10.(2^2+y^2)^2-4x^2y^2=(4+y^2-2xy)(4+y^2+2xy)
11.1-4a^2-9b^2+12ab=1-(2a-3b)^2=(1+2a-3b)(1-2a+3b)