Let ${}^n{C_r}$ denote the binomial coefficient of x^r in the expansion of (1 + x)ⁿ. If $\sum\limits_{k = 0}^{10} {({2^2} + 3k)} {}^{10}{C_k} = \alpha {.3^{10}} + \beta {.2^{10}},\alpha ,\beta \in R$, then $\alpha$ + $\beta$ is equal to ___________.