1. **State the problem:** We have a rectangle ABCD with sides labeled as follows:
- AB = $2x + 5y$
- BC = $x + 1$
- AD = $3y$
- DC = $x + 4y + 7$
We need to:
a) Write two equations relating $x$ and $y$.
b) Solve these equations to find $x$ and $y$.
c) Find the area of the rectangle.
2. **Form the equations:** Since ABCD is a rectangle, opposite sides are equal in length.
- So, AB = DC gives:
$$2x + 5y = x + 4y + 7$$
- And AD = BC gives:
$$3y = x + 1$$
3. **Simplify the first equation:**
$$2x + 5y = x + 4y + 7$$
Subtract $x$ and $4y$ from both sides:
$$2x - \cancel{x} + 5y - \cancel{4y} = \cancel{x} + 4y - \cancel{4y} + 7$$
$$x + y = 7$$
4. **Rewrite the second equation:**
$$3y = x + 1$$
Rearranged:
$$x - 3y = -1$$
5. **Solve the system using elimination:**
Equations:
$$x + y = 7$$
$$x - 3y = -1$$
Subtract the second from the first to eliminate $x$:
$$\cancel{x} + y - (\cancel{x} - 3y) = 7 - (-1)$$
$$y - (-3y) = 7 + 1$$
$$y + 3y = 8$$
$$4y = 8$$
$$y = 2$$
6. **Find $x$ using $x + y = 7$:**
$$x + 2 = 7$$
$$x = 5$$
7. **Calculate the area of the rectangle:**
Area = length × width
Using AB and BC:
$$\text{Area} = (2x + 5y)(x + 1)$$
Substitute $x=5$, $y=2$:
$$= (2(5) + 5(2))(5 + 1)$$
$$= (10 + 10)(6)$$
$$= 20 \times 6 = 120$$
**Final answers:**
- $x = 5$
- $y = 2$
- Area = 120 cm²
Rectangle Variables 24176F
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