If $A M$ and GM of roots of a quadratic equation are 5 and 4 , respectively, then the quadratic equation is

Given that $$a, b$$ and $$x$$ are real numbers and $$a < b, x < 0$$, then

If $$\alpha$$ and $$\beta$$ are roots of the equation $$x^2=x+1=0$$, then $$\alpha^2+\beta^2$$ is