Phan tich da thuc sau thanh nhan tu ( help me please :< )
1/ x2 - 2xy + y2 - 4
2/ a2 - 30ab + 15b2 - 60c2
3/ 18m2 - 36mn + 18n2 - 72p2
4/ 9a2 - 18ab + 9b2 - 36c2
5/ 5a ( x - 3y ) + 8b ( 3y - x )
6/ 7x2 - 14xy + 7y2 - 7z2
7/ 3x2 - 3y2 - 5x + 5y
8/ x2 - xy + 5x - 5y
9/ 2x2 - 5x -7
10/ 14x2y - 21xy2 + 28x2y2
11/ x(x-y) - 5x + 5y
1: \(=\left(x-y\right)^2-4=\left(x-y-2\right)\left(x-y+2\right)\)
3: \(=18\left(m^2-2mn+n^2-4p^2\right)\)
\(=18\left(m-n-2p\right)\left(m-n+2p\right)\)
4: \(=9\left(a^2-2ab+b^2-4c^2\right)\)
\(=9\left(a-b-2c\right)\left(a-b+2c\right)\)
5: \(=\left(x-3y\right)\left(5a-8b\right)\)
6: \(=7\left(x^2-2xy+y^2-z^2\right)\)
\(=7\left(x-y-z\right)\left(x-y+z\right)\)
