Let f(x)=x2−6x2−4x+5 ⇒f(−x)=−x5−6x2+4x+5 Number of changes of sign in f(x) are 2 and number of changes of sign in f(−x) are 1 . ∴ By descarte's rule of signs Maximum number of +ve real roots are 2 and -ve real roots are 1. ∴ Maximum possible real roots are 3 .