__Example__The roots of $2{x}^{2}+3x-1=0$ are α and β. Find the values of

(a) $(\alpha +1)(\beta +1)$

(b) $\frac{1}{\alpha}+\frac{1}{\beta}$

(c) ${\alpha}^{2}\beta +\alpha {\beta}^{2}$

(d) $\frac{\alpha}{\beta}+\frac{\beta}{\alpha}$

*[Clue: ${\alpha}^{2}+{\beta}^{2}={(\alpha +\beta )}^{2}-2\alpha \beta $ ]*