Consider the function $f(x) = \displaystyle \frac { 2 x + 7 } { 3 x + 3 }$. For this function there are two important intervals: $(-\infty, A)$ and $(A,\infty)$ where the function is not defined at $A$. Determine $A$.

$A=$

For each of the following intervals, tell whether $f(x)$ is increasing (input INC ) or decreasing (type in DEC ).

$(-\infty, A)$:
$(A,\infty)$:  

Note that this function has no inflection points, but we can still consider its concavity. For each of the following intervals, tell whether $f(x)$ is concave up (input CU ) or concave down (type in CD ).

$(-\infty, A)$:
$(A,\infty)$: