Question

phân tích đa thức thành nhân tử

a/4x-3x-1

b/x^7+x^5+1

c/x^3-x^2-4

d/3x^3-7x^2+17x-5

e/x^2+2xy+y^2-x-y-12

Answer 1

a: \(4x^2-3x-1\)

\(=4x^2-4x+x-1=\left(x-1\right)\left(4x+1\right)\)

b: \(=x^7+x^6+x^5-x^6-x^5-x^4+x^5+x^4+x^3-x^3+1\)

\(=\left(x^2+x+1\right)\left(x^5-x^4+x^3\right)-\left(x-1\right)\left(x^2+x+1\right)\)

\(=\left(x^2+x+1\right)\left(x^5-x^4+x^3-x+1\right)\)

c: \(=x^3-2x^2+x^2-4\)

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

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

e: \(=\left(x+y\right)^2-\left(x+y\right)-12\)

\(=\left(x+y-4\right)\left(x+y+3\right)\)