If x² $$-$$ px + 4 > 0 for all real values of x, then which one of the following is correct?

If one root of the equation (l $$-$$ m) x² + lx + 1 = 0 is double the other and l is real, then what is the greatest value of m?

The roots of the equation $$(q - r){x^2} + (r - p)x + (p - q) = 0$$ are

The sum of all real roots of the equation $${\left| {x - 3} \right|^2} + \left| {x - 3} \right| - 2 = 0$$ is