To calculate the profit function, we subtract the cost function \( C(x) \) from the revenue function \( R(x) \). The profit function \( P(x) \) can be expressed as follows:
\[ P(x) = R(x) - C(x) \]
Substituting the expressions for \( R(x) \) and \( C(x) \):
\[ P(x) = 16x - (12x + 120) \]
Now, simplify \( P(x) \):
\[ P(x) = 16x - 12x - 120 \]
\[ P(x) = 4x - 120 \]
Now, we want to determine how many units must be produced for the business to make a profit of $460. We set \( P(x) \) equal to 460:
\[ 4x - 120 = 460 \]
Next, add 120 to both sides:
\[ 4x = 460 + 120 \]
\[ 4x = 580 \]
Now, divide by 4:
\[ x = \frac{580}{4} = 145 \]
Thus, the business must produce 145 units to make a profit of $460.