Question

If alpha and beta are zero of the equation x2+7x+7 find the value of 1/alpha + 1/beta - 2alpha beta.

Answer 1

$$\begin{gathered} \mathrm{Hi}, \\ {\mathrm{x}}^2+7\mathrm{x}+7=0 \\ \mathrm{\alpha }+\mathrm{\beta }=\frac{-coefficientofx}{coefficientof{x}^2}=-7 \\ \mathrm{\alpha \beta }=\frac{\cos n\tan tterm}{coefficientof{x}^2}=7 \\ \mathrm{so} \\ \frac{1}{\mathrm{\alpha }}+\frac{1}{\mathrm{\beta }}-2\mathrm{\alpha \beta }=\frac{\mathrm{\alpha }+\mathrm{\beta }}{\mathrm{\alpha \beta }}-2\mathrm{\alpha \beta }=\frac{-7}{7}-2\times 7=-1-14=-15 \end{gathered}$$