Question

Gải phương trình sau: x⁴+2x³-2x²+2x-3=0

Answer 1

 x⁴+2x³-2x²+2x-3=0

=>  (x⁴ - 1) + (2x³-2x² )+ (2x-2)=0

=> (x - 1).(x+1).(x² + 1) + 2x².(x - 1) + 2.(x -1) = 0

=> (x -1). [(x+1).(x² + 1) + 2x² + 2] = 0

<=> (x - 1). (x³ + x + x² + 1 + 2x² + 2)= 0

<=> (x - 1). (x³ + x + 3x² + 3)= 0

<=> x - 1 = 0 hoặc x³ + x + 3x² + 3 = 0

+) x - 1 = 0 => x  =1 

+) x³ + x + 3x² + 3 = 0 <=> x. (x² + 1) + 3.(x² + 1) = 0

<=> (x+3). (x² +1) = 0 <=> x + 3 = 0 (vì x² + 1 > 0 với mọi x)

<=> x = -3

Vậy pt có 2 nghiệm x = 1 ; x = -3

Answer 2

X^4+2X^3-X^2+2X+1=0 LAM TN

Answer 3

(x^4+x^3+x+1)/(x^4-x^3+2x^2-x+1)>=0