Q.
If $x, y \in R$ satisfy the equation $3 x^2+2 y^2-6 y-3 x+\frac{21}{4}=0$, then the value of $\displaystyle\sum_{r=0}^{10}(2 y+r x)=$ $k$ then find the value of $\left[\frac{k}{11}\right]$.
[Note: $[x]$ denotes greatest integer less than or equal to $x$.]
Complex Numbers and Quadratic Equations
Solution: