Question

PTĐTTNT : x^3 - x^2 - 7x + 15

Answer 1

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

Answer 2

x^3-x^2-7x+15=0

<=> x^3+3x^2-4x^2-12x+5x+15=0

<=> x^2(x+3)-4x(x+3)+5(x+3)=0

<=> (x+3)(x^2-4x+5)=0

<=> x+3=0 vì x^2-4x+5 khác 0

<=> x=-3

Answer 3

(x+3)(x²-4x+5)