We can expand the expression using the distributive property:
$(12-9i)(8+15i) = 12(8) + 12(15i) - 9i(8) - 9i(15i)$.
Simplifying, we get:
$96 + 180i - 72i - 135i^2$.
Since $i^2 = -1$, we can substitute $-1$ for $i^2$:
$96 + 180i - 72i - 135(-1)$.
Continuing to simplify, we get:
$96 + 180i - 72i + 135$.
Combining like terms, we get:
$231 + 108i$.
The absolute value of a complex number $a + bi$ is given by $\sqrt{a^2 + b^2}$.
So the absolute value of $231 + 108i$ is $\sqrt{231^2 + 108^2}$.
Calculating, we get:
$\sqrt{53361 + 11664} = \sqrt{65025} = \boxed{255}$.
The answer is: 255
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
What is the absolute value of $(12-9i)(8+15i)$?

### Answer:
