1. а) 2x-4y=2(x-2y) б) 5m²b-10mb= 5mb(m-2) в)6x-4= 2(3x-2) г) 7m²b-14mb= 7mb( m-2) д)(3x+2n)²= 9x²+12xn+4n² е)(3c+4n)(4n-3c)= (4n)²-(3c). д) 3x-6y= 3(x-2y) e) 9x²y+18xy= 9xy(x+2)
2. а) (4m-2n)²= 16m²-16mn+4n² б) (6z+5s)(5s-6z)= (5s)²-(6z)² в) (3m+2n)²= 9m²+12mn+4n² г) (4z+5s)(5s-4z) = (5s)²-(4z)² д) (3x+2n) = 9x²+ 12xn+ 4n² е) (3c+4n)(4c-3n)= (4c)²-(3n)²