Đáp án+Giải thích các bước giải:
5, 10ax-5ay+2x-y
=(10ax+2x)-(5ay+y)
=2x(5a+1)-y(5a+1)
=(5a+1)(2x-y)
7, 5x²-5xy-7x+7y
=5x(x-y)-7(x-y)
=(5x-7)(x-y)
9, 2x²+2x+xy+y
=2x(x+1)+y(x+1)
=(2x+y)(x+1)
11, 5a²-5
=5(a²-1)
=5(a-1)(a+1)
13, 3x²-12x
=3x(x²-4)
=3x(x+2)(x-2)
15, 9xy-4a²xxy
=xy(9-4a²)
=xy(3-2a)(3+2a)
17, a²-b²+3a+3b
=(a-b)(a+b)+3(a+b)
=(a+b)(a-b+3)
19, x²-y+ã-ay
=(x-y)(x+y)+a(x-y)
=(x-y)(x+y+a)
21, 5x²-5y²-x+y
=5(x²-y²)-(x-y)
=5(x-y)(x+y)-(x-y)
=5(x-y)(x+y-1)
23, x²-y²-4x+4y
=(x-y)(x+y)-4(x-y)
=(x-y)(x+y-4)
25, x²-9+(x-3)²
=(x-3)(x+3)+(x-3)²
=(x-3)(x+3+x-3)
=(x-3)2x
27, 2x²-4x+2
=2(x²-2x+1)
=2(x-1)²
29, -3x²-6x-3
=-3(x²+2x+1)
=-3(x+1)²
31, 2x³+8x²+8x
=2x(x²+4x+4)
=2x(x+2)²
33, 6x²+12xy+6y²
=6(x²+2xy+y²)
=6(x+y)²
35, 2x³-4x²+2x
=2x(x²-2x+1)
=2x(x-1)²
37, 4x^5y²-8x^4y²+4x³y²
=4x³y²(x²-2x+1)
=4x³y²(x-1)²
39, 12x²-(2xy+3y²)
=3(4x²-4xy+y²)
=3(2x-y)²
41, 20x^4y²-20x³y³+5x²y^4
=5x²y²(4x²-4xy+1)
=5x²y²(2x-1)²
43, -12x^4y+12x³y²-3x²y³
=-3x²y(4x²+4xy-y²)
=-3x²y(2x-y)²
45, x²-2xy+y²-4
=(x-y)²-4
=(x-y-4)(x-y+4)
47, x²+4xy+4y²-9
=(x+y)²-9
=(x-2y-9)(x+2y-9)
49, a²+4a+4-b²
= (a+2)²-b²
= (a-2-b)(a+2-b)
51, x²-4xy+4y²-36z²
= (x-2y)-36z²
= (x-2y-6z)(x-2y+6z)
53, x²+2xy+y²-16a²
= (x+y)²-16a²
= (x+y-4a)(x-y+4a)
55, x+6x-4y²+9
=(x²+6x+9)-4y²
=(x+3)²-4y²
=(x+3-2y)(x+3+2y)
57, a²-b²+2a+1
=(a²+2a+1)-b²
=(a+1)-b²
=(a+1)-b²
=(a+1-b)(a+1+b)
59, x²+6x-4y²+9
=(x²+6x+9)-4y²
=(x+3)²-4y²
=(x+3+2y)(x+3-2y)
61, x²-25+y²-2xy
=(x-2xy+y²)-25
=(x-y)²-25
=(x-y-5)(x-y+5)
63, y²-(x-2x+1)
=y²-(x-1)²
=(y-x-1)(y-x+1)
65, 25a²b²-4x²+4x+1
=25a²b²-(2x-1)²
=(5ab-2x+1)(5ab+2x-1)
67, y²-9x²+6x-1
=y²-(3x-1)
=(y-3x+1)(y+3x-1)
