How to solve this? $f=(2x^2-x-1)^10$ Calculate $x_1+x_2+x_3+...+x_20$ .

Question

1572 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-03-26T17:08:27

$5$

$2x^2-x-1 =2 (x+1/2)(x-1)$ and

$(2x^2-x-1)^10=2^10(x+1/2)^10(x-1)^10$ so the sum of their $20$ roots is $x_1+x_2+cdots+x_20 = 10 xx 1-10 xx 1/2 = 5$

How to solve this?f=(2x^2-x-1)^10f=(2x^2-x-1)^10Calculate x_1+x_2+x_3+...+x_20x_1+x_2+x_3+...+x_20.