Posted by **chirag** on Tuesday, February 12, 2013 at 9:41am.

x is a number such that x2+3x+9=0. What is the value of x3?

- maths -
**Steve**, Tuesday, February 12, 2013 at 10:15am
since (x-3)(x^2+3x+9) = x^3 - 3^3

x^3 - 3^3 = 0

x^3 = 27

- WoW at Steve - maths -
**Reiny**, Tuesday, February 12, 2013 at 11:52am
What a great way to do this question.

Did you see the round-about way I used ??

http://www.jiskha.com/display.cgi?id=1360597831

I was even thinking of using DeMoivre's theorem.

- WoW at Reiny - maths -
**Steve**, Tuesday, February 12, 2013 at 4:07pm
I was going to show an alternative direct solution, but when I saw where it was headed, I blew it off.

Can't believe you

(a) slogged through it all

(b) got it right!

## Answer This Question

## Related Questions

- maths - N is an even 3-digit number such that the last 3 digits of N*N are N ...
- maths - The function f is such that f(x)= (2 - x)^2, x belongs to real number. ...
- Maths question - (a) find the largest four digit number which has a total of ...
- Maths - (a) find d largest four digit number which has a total of exactly 3 ...
- maths - Ramesh buys 150 shares of par value ` 10/- each of a company which pays ...
- Maths - I have a three digit number such that the sum of the cubes of each digit...
- maths - find value of p such that the equation (x+1)(x+2)=p
- Maths - Find the two digit number such that if you treble it and you take away ...
- applied maths - find the value of b such that u=(-2,4,2) ¡ì v=(b,b^2,1) are ...
- maths - If a and b are coprime positive integers such that 1/2+1/3+1/4+1/5=a/b, ...

More Related Questions