Question

PTĐTTNT
a) x³ - 3x² + 1 - 3x
b) 3x² - 7x - 10

Answer 1

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

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

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

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

b) \(3x^2-7x-10=3x^2+3x-10x-10\)

\(=3x\left(x+1\right)-10\left(x+1\right)\)

\(=\left(x+1\right)\left(3x-10\right)\)

Answer 2

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

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

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

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

b) \(3x^2-7x-10=\left(3x^2+3x\right)-\left(10x+10\right)\)

= \(3x\left(x+1\right)-10\left(x+1\right)\)

= \(\left(x+1\right)\left(3x-10\right)\)