✔ 最佳答案
1) 6px+8py
= 2p(3x+4y)
2) 15ax-5ay
=5a(3x-y)
3) -8ay+12ax
= 4a(-2y+3x)
= 4a(3x-2y)
4) -9qx-15xp
= -3x(3q+5p)
5) 56x^2+8
=8(x^2+1)
6) 4x^2+18
=2(2x^2+9)
7) 9x+12x^2
= 3x(3+4x)
8) -3bx^2+6b
=3b(-x^2+2)
=3b(2-x^2)
9) x^2(x-2y)-y^2(2y-x)
=x^2(x-2y)+y^2(x-2y)
=(x^2+y^2)(x-2y)
10) -6p+4q-8r
=2(-3p+2q-4r)
11) a^3b^2+a^2b+ab^3
=ab(a^2b+a+b^2)
12) pq+pr+q+r
=p(q+r)+(q+r)
=(p+1)(q+r)
13) x-y+x^2-xy
=(x-y)+x(x-y)
=(x-y)(1+x)
14) 4ac+4ad+5bd+5bc
=4a(c+d)+5b(d+c)
=(4a+5b)(c+d)
15) x^4+x^2y+3x^2+3y
=(x^4+3x^2)+(x^2y+3y)
=x^2(x^2+3)+y(x^2+3)
=(x ^2+y)(x^2+3)
16) 2x^2+9x+4
=(2x+1)(x+4)
17) 3x^2+17x+20
=(3x+5)(x+4)
18) 3-8x-3x^2
=(3+x)(1-3x)
19) 18c^2+9cd+d^2
=(3c+d)(6c+d)
20) 4a^2-8ab-5b^2
=(2a-5b)(2a+b)
21) 2m^2+3mn-35n^2
=(2m-7n)(m+5n)
22) 2p^2+10q^2-9pq
=(2p-5q)(p-2q)
23) 4a^2-9b^2
=(2a)^2-(3b)^2
=(2a+3b)(2a-3b)
24) 7x^2-28
=7(x^2-2^2)
=7[(x+2)(x-2)]
25) 2x^2-8y^2
=2x^2-2(2y)^2
=2[x^2-(2y)^2]
=2[(x+2y)(x-2y)]
26) (m+n)^2-(p-q)^2
=[(m+n)+(p-q)][(m+n)-(p-q)]
=(m+n+p-q)(m+n-p+q)
27) 9p^2-16r^2q^2
=(3p)^2-(4rq)^2
=(3p+4rq)(3p-4rq)
28) 12k^2-27(k-1)^2
=12k^2-27(k^2-2k+1)
=12k^2-27k^2+54k-27
=-15k^2+54k-27
=-(15k^2-54+27)
=-(5k-3)(3k-9)
29) 4(3x-y)^2-9(2x+y)^2
=[2(3x-y)]^2-[3(2x+y)]^2
=[2(3x-y)+3(2x-y)][2(3x-y)-3(2x-y)]
=(6x-2y+6x-3y)(6x-2y-6x+3y)
=(12x-5y)y
30) (a^-2b)^-1/a^-3
=a^3 / (a^2-2b)
31) (a^2b)-2/ab
=(a^3b^2-2) / (ab)
32) x^2y/(xy)^-3
=(x^2y)(xy)^3
=x^5y^4
33) (a/b)^3.b^5/a^7
=(a^3b^5) / (b^3a^7)
=b^4 / a^4
= (b/a)^4
34)x^-3y/x^2
=y / x^5
35) 3m^3/(3mn)^2
= 3m^3 / (9m^2n^2)
= m / (3n^2)
36) (2ab^2)^2/6a^5
= (4a^2b^4) / (6a^5)
= (2b^4) / (3a^3)