Question

Find the sum of real roots of the equation $a^6-7a^3-8$

Answer 1

$(a^3{)}^2-7a^3-8=0(a^3{)}^2-8a^3+a^3-8=0a^3(a^3-8)+1(a^3-8)=0(a^3+1)(s^3-8)=0\therefore a^3=-1or{a}^3=8\therefore a=-1ora=2hencesumofroots=-1+2=1$