1. **State the problem:** Find two positive numbers $x$ and $y$ such that $x + 2y = 100$ and the product $P = xy$ is maximized.
2. **Express one variable in terms of the other:** From the constraint, $x + 2y = 100$, solve for $x$:
$$x = 100 - 2y$$
3. **Write the product function:**
$$P = xy = (100 - 2y) y = 100y - 2y^2$$
4. **Maximize the product:** To find the maximum, take the derivative of $P$ with respect to $y$ and set it to zero:
$$\frac{dP}{dy} = 100 - 4y = 0$$
5. **Solve for $y$:**
$$100 - 4y = 0 \implies 4y = 100 \implies y = \frac{100}{4} = 25$$
6. **Find $x$ using $y=25$:**
$$x = 100 - 2(25) = 100 - 50 = 50$$
7. **Check the product:**
$$P = xy = 50 \times 25 = 1250$$
8. **Verify maximum with second derivative:**
$$\frac{d^2P}{dy^2} = -4 < 0$$ which confirms a maximum.
**Final answer:** The two positive numbers are $x = 50$ and $y = 25$.
Note: The answer $2 \frac{1}{4}$ given does not match the problem's solution for maximum product under the given constraint.
Max Product 57B3Bc
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.