Rectangle Sides 43357F
1. **State the problem:** We are given a rectangle ABCD with sides DC and AD defined as functions of $x$:
$$DC = \frac{5}{x^2 - 25}$$
$$AD = \frac{3}{x - 5}$$
We want to understand these expressions and possibly simplify or analyze them.
2. **Recall the formula for the area of a rectangle:**
$$\text{Area} = \text{length} \times \text{width}$$
Here, the sides DC and AD represent the length and width.
3. **Simplify the expressions:**
Note that $x^2 - 25$ is a difference of squares:
$$x^2 - 25 = (x - 5)(x + 5)$$
So,
$$DC = \frac{5}{(x - 5)(x + 5)}$$
4. **Express the area:**
$$\text{Area} = DC \times AD = \frac{5}{(x - 5)(x + 5)} \times \frac{3}{x - 5} = \frac{15}{(x - 5)^2 (x + 5)}$$
5. **Important domain restrictions:**
- $x \neq 5$ because it makes denominators zero.
- $x \neq -5$ for the same reason.
6. **Summary:**
- Side DC is $\frac{5}{(x - 5)(x + 5)}$
- Side AD is $\frac{3}{x - 5}$
- Area is $\frac{15}{(x - 5)^2 (x + 5)}$
These expressions describe the rectangle's sides and area as functions of $x$ with domain restrictions to avoid division by zero.