If x * y = x² + y² - xy, then the value of 9 * 11 is?

Solution (By Examveda Team)

$$\eqalign{ & x*y = {x^2} + {y^2} - xy \cr & {\text{ }}9*11 = {\left( 9 \right)^2} + {\left( {11} \right)^2} - 11 \times 9 \cr & \Rightarrow 9*11 = 81 + 121 - 99 \cr & \Rightarrow 9*11 = 103 \cr} $$