giúp em với ạ
Bài 1:
1: \(a^3-a^2b+a-b\)
\(=a^2\left(a-b\right)+\left(a-b\right)\)
\(=\left(a-b\right)\left(a^2+1\right)\)
2: \(x^3+3x^2-xy^2-3y^2\)
\(=x^2\left(x+3\right)-y^2\left(x+3\right)\)
\(=\left(x+3\right)\left(x^2-y^2\right)=\left(x+3\right)\left(x-y\right)\left(x+y\right)\)
Bài 2:
1: x(a+b)-a-b
=x(a+b)-(a+b)
=(a+b)(x-1)
2: x(a-b)+a-b
=x(a-b)+(a-b)
=(a-b)(x+1)
3: x(a+b)+a+b
=x(a+b)+(a+b)
=(a+b)(x+1)
4: m(x-y)+x-y
=m(x-y)+(x-y)
=(x-y)(m+1)
5: x+y+a(x+y)
=(x+y)+a(x+y)
=(x+y)(a+1)
6: x-y-a(x-y)
=(x-y)-a(x-y)
=(x-y)(1-a)
8: \(a\left(x+y\right)-x-y\)
\(=a\left(x+y\right)-\left(x+y\right)\)
=(x+y)(a-1)
9: \(x\left(a-b\right)-a+b\)
\(=x\left(a-b\right)-\left(a-b\right)\)
\(=\left(a-b\right)\left(x-1\right)\)
10: \(-a-b+x(a+b)\)
\(=-\left(a+b\right)+x\left(a+b\right)\)
\(=\left(a+b\right)\left(x-1\right)\)
11: \(xz+yz-5\left(x+y\right)\)
\(=z\left(x+y\right)-5\left(x+y\right)\)
\(=\left(x+y\right)\left(z-5\right)\)
12: ax+ay-bx-by
=a(x+y)-b(x+y)
=(x+y)(a-b)
13: ax+ay-2x-2y
=a(x+y)-2(x+y)
=(x+y)(a-2)
14: \(-2x-2y+ax+ay\)
\(=-2\left(x+y\right)+a\left(x+y\right)\)
=(x+y)(a-2)
15: \(x^2+xy-2x-2y\)
=x(x+y)-2(x+y)
=(x+y)(x-2)
16: \(x^2-xy+2x-2y\)
\(=x\left(x-y\right)+2\left(x-y\right)\)
\(=\left(x-y\right)\left(x+2\right)\)
17: \(10ax-5ay+2x-y\)
\(=5a\left(2x-y\right)+\left(2x-y\right)\)
=(2x-y)(5a+1)
18: \(3x^2-3xy-5x+5y\)
\(=3x\left(x-y\right)-5\left(x-y\right)\)
\(=\left(x-y\right)\left(3x-5\right)\)
19: \(5x^2y+5xy^2-a^2x-a^2y\)
\(=5xy\left(x+y\right)-a^2\left(x+y\right)\)
\(=\left(x+y\right)\left(5xy-a^2\right)\)
20: \(x^3+2x^2-2x-1\)
\(=\left(x^3-1\right)+2x\left(x-1\right)\)
\(=\left(x-1\right)\left(x^2+x+1\right)+2x\left(x-1\right)\)
\(=\left(x-1\right)\left(x^2+x+1+2x\right)=\left(x-1\right)\left(x^2+3x+1\right)\)
