RRB Junior Engineer Stage 1 Model Papers 4

Expression $=\left(\mathit{x}\mathit{–}2\right)\left(\mathit{x}\mathit{–}9\right)$
$={\mathit{x}}^2-11\mathit{x}+18=\mathit{a}{\mathit{x}}^2+\mathit{b}\mathit{x}+\mathit{c}$
Minimum value Alternate Method:
In this type of questions take $\left(\mathit{x}\mathit{–}\mathit{a}\right)\left(\mathit{x}\mathit{–}\mathit{b}\right)=0$ and value of $\mathit{x}=\frac{\mathit{a}+\mathit{b}}{2}$ for minimum value and $\mathit{x}=\mathit{a}+\mathit{b}$ for maximum value of equation.
Required value