To find the amount of spending \( x \) on marketing that maximizes profit \( P \), we can use the formula for the vertex of a parabola given in the standard form \( P = ax^2 + bx + c \). The maximum or minimum value of a quadratic function represented by this form occurs at \( x = -\frac{b}{2a} \).
In your equation, \( P = -5x^2 + 1000x + 5000 \):
- \( a = -5 \)
- \( b = 1000 \)
- \( c = 5000 \)
Now, we can calculate the vertex:
\[ x = -\frac{b}{2a} = -\frac{1000}{2(-5)} = -\frac{1000}{-10} = 100 \]
Thus, the amount to spend on marketing to achieve maximum profit is \( x = 100 \) thousand dollars.
So, the company should direct $100,000 toward marketing.