[toán 8] đại

N

nguyenbahiep1

x^5-x^4-x^3=x^2+x+2
Bấm để xem đầy đủ nội dung ...

[laTEX] x^5-2x^4 +x^4-2x^3+x^3-2x^2 +x^2-2x+x-2 = 0 \\ \\ x^4(x-2)+x^3(x-2)+x^2(x-2) +x(x-2)+x-2 = 0 \\ \\ (x-2)(x^4+x^3+x^2+x+1) = 0 \\ \\ TH_1: x=2 \\ \\ TH_2: x^2 + x + 1 + \frac{1}{x} + \frac{1}{x^2} = 0 \\ \\ (x+\frac{1}{x})^2 + (x+\frac{1}{x}) -1 = 0 \\ \\ u = x+\frac{1}{x} \\ \\ u^2 +u-1 = 0 \\ \\ u = \frac{-1 \pm \sqrt{5}}{2}[/laTEX]
 
Last edited by a moderator:
You must log in or register to reply here.
Top Bottom