5: \(3x\left(x+5\right)-2\left(x+5\right)=\left(x+5\right)\left(3x-2\right)\)
8: \(x\left(y-1\right)-y\left(1-y\right)\)
\(=x\left(y-1\right)+y\left(y-1\right)\)
=(y-1)(x+y)
11: \(3x\left(x-2\right)+5\left(2-x\right)\)
\(=3x\left(x-2\right)-5\left(x-2\right)\)
=(x-2)(3x-5)
14: \(3\left(x-y\right)-5x\left(y-x\right)\)
\(=3\left(x-y\right)+5x\left(x-y\right)\)
\(=\left(x-y\right)\left(5x+3\right)\)
17: \(x\left(2y-1\right)-5\left(2y-1\right)=\left(2y-1\right)\left(x-5\right)\)
20: \(3x\left(x-y\right)+6\left(y-x\right)\)
\(=3x\left(x-y\right)-6\left(x-y\right)\)
\(=\left(x-y\right)\left(3x-6\right)=3\left(x-2\right)\left(x-y\right)\)
6: \(x^2\left(x-1\right)+4\left(x-1\right)=\left(x-1\right)\left(x^2+4\right)\)
9: \(y\left(x-2\right)-3\left(2-x\right)\)
\(=y\left(x-2\right)+3\left(x-2\right)\)
\(=\left(x-2\right)\left(y+3\right)\)
12: \(7x\left(x-y\right)-\left(y-x\right)\)
\(=7x\left(x-y\right)+\left(x-y\right)\)
\(=\left(x-y\right)\left(7x+1\right)\)
15: \(x\left(x-y\right)+y\left(y-x\right)\)
\(=x\left(x-y\right)-y\left(x-y\right)\)
=(x-y)(x-y)
\(=\left(x-y\right)^2\)
18: \(9\left(x-2y\right)+x\left(2y-x\right)\)
\(=9\left(x-2y\right)-x\left(x-2y\right)\)
\(=\left(x-2y\right)\left(9-x\right)\)
21: \(5x\left(x-1\right)-15x\left(1-x\right)\)
\(=5x\left(x-1\right)+15x\left(x-1\right)\)
\(=20x\left(x-1\right)\)
24: \(20x\left(x+y\right)-8y\left(x+y\right)\)
\(=\left(x+y\right)\left(20x-8y\right)\)
\(=4\left(5x-2y\right)\left(x+y\right)\)
27: \(9x^2\left(y+z\right)+3x\left(y+z\right)\)
\(=\left(y+z\right)\left(9x^2+3x\right)\)
\(=3x\left(3x+1\right)\left(y+z\right)\)
giúp mình với ạ, mình cần gấp lắm ạ
