The quadratic equation 2x2+kx+6=0 depends on the real parameter k.
a. (i) Find the value(s) of k for which the equation has equal real roots.
b. (ii) Taking the positive value of k obtained in part (i), determine the root(s) of the equation.
c. (iii) Using the root(s) found in part (ii), evaluate 5x2−4x.