SAT Right triangles Question

The function $p$ is defined by $p(x)=a((x+6{)}^2-b)((x+6{)}^2-c)$ , where $a,b$ , and $c$ are constants. In the $xy$ -plane, the graph of $y=p(x)$ passes through the points (-7, 24) and (0, 899). What is the value of $p(-12)+p(-5)$ ?