Question

phân tích đa thức thành nhân tử

a) x²-y²-5x+5y

b)5x³-5x²y-10x²+10xy

c)2x²-5x-7

Giups tui vs mn

Answer 1

a)

\(=\left(x^2-y^2\right)-\left(5x-5y\right)=\left(x-y\right)\left(x+y\right)-5\left(x-y\right)=\left(x-y\right)\left(x+y-5\right)\)

b)

\(=\left(5x^3-5x^2y\right)-\left(10x^2-10xy\right)=5x^2\left(x-y\right)-10x\left(x-y\right)=\left(x-y\right)\left(5x^2-10x\right)=5x\left(x-y\right)\left(x-2\right)\)

c)

\(=2x^2+2x-7x-7\)

\(=2x\left(x+1\right)-7\left(x+1\right)=\left(x+1\right)\left(2x-7\right)\)

 

Answer 2

\(a\)) \(=\left(x^2-y^2\right)-\left(5x-5y\right)\)

\(=\left(x-y\right).\left(x+y\right)-5.\left(x+y\right)\)

\(=\left(x+y\right).\left(x-y-5\right)\)

\(b\)) \(=\left(5x^3-5x^2y\right)-\left(10x^2+10xy\right)\)

\(=5x^2.\left(x-5y\right)-10x.\left(x-5y\right)\)

\(=\left(x-5y\right).\left(5x^2-10x\right)\)

\(=5x.\left(x-2\right).\left(x-5y\right)\)

\(c\)) \(=2x^2+2x-7x-7\)

\(=\left(2x^2+2x\right)-\left(7x+7\right)\)

\(=2x.\left(x+1\right)-7.\left(x+1\right)\)

\(=\left(x+1\right).\left(2x-7\right)\)