$(x-a)(x-b)+h^2=0$, find the value of "h" when the roots of the equation are real(a>b). If The roots are $\alpha,\beta$,Then find the quadratic equations which have the roots of $(2\alpha+\beta),(\alpha+2\beta)$ By the correct substitution....

In this problem i find the value of "h" like this h<= $\frac{a-b}{2}$ But, How can i find that quadratic equations by substituting...