Find the marginal profit of a firm with a profit function:
$$P(q) = -192q + 88q^2 - 16q^3$$
I got
$$\frac{dP}{dq} = -192 + 176q - 48q^2$$
However, the solution reads
$$ \frac{dP}{dq}= -4(q-2)(q-4)(q-6)$$
Is this a typo, or am I missing something?