Garden Area A270Ab
1. **Problem Statement:**
We have a rectangular garden with dimensions $(2x + 3)$ metres and $(x - 1)$ metres.
2. **Write an expression for the area:**
The area $A$ of a rectangle is given by the formula:
$$A = \text{length} \times \text{width}$$
Here, length = $2x + 3$ and width = $x - 1$.
So,
$$A = (2x + 3)(x - 1)$$
3. **Expand the expression:**
Use the distributive property (FOIL method):
$$A = 2x \times x + 2x \times (-1) + 3 \times x + 3 \times (-1)$$
$$A = 2x^2 - 2x + 3x - 3$$
Simplify like terms:
$$A = 2x^2 + x - 3$$
4. **Calculate the area when $x = 5$:**
Substitute $x = 5$ into the expanded expression:
$$A = 2(5)^2 + (5) - 3 = 2(25) + 5 - 3 = 50 + 5 - 3 = 52$$
So, the area is 52 square metres.
5. **Factorise the expanded expression:**
We want to factorise:
$$2x^2 + x - 3$$
Find two numbers that multiply to $2 \times (-3) = -6$ and add to $1$ (the coefficient of $x$).
These numbers are 3 and -2.
Rewrite the middle term:
$$2x^2 + 3x - 2x - 3$$
Group terms:
$$(2x^2 + 3x) - (2x + 3)$$
Factor each group:
$$x(2x + 3) - 1(2x + 3)$$
Factor out common binomial:
$$(2x + 3)(x - 1)$$
6. **Verification:**
The factorised form matches the original expression for the area.
**Final answers:**
- a) Area expression: $A = (2x + 3)(x - 1)$
- b) Expanded: $A = 2x^2 + x - 3$
- c) Area at $x=5$: $52$ square metres
- d) Factorised: $A = (2x + 3)(x - 1)$