M4maths Previous Puzzles

11 Sep 2012 solve

x + x^2 + y + y^3 = 16
and x = y
then no. of possible real values of x are

OPtion

1) 0
2) 1
3) 2
4) 3
5) 4
6) 5
7) 6
8) 7
9) 8
10) none of these

Solution

on putting x = y in other given equation
x + x^2 + y + y^3 = 16, we get
x + x^2 + x + x^3 = 16
or 2x + x^2 + x^3 = 16
x=2 is a root of this equation and other 2 roots are imaginary

Correct Option: 2 Best Solution (0)