1. Problem 28: Write an algebraic expression for the area of a rectangular rug and find an equivalent expression using properties of operations.
The area $A$ of a rectangle is given by the formula:
$$A = \text{length} \times \text{width}$$
If the length is $l$ and the width is $w$, then the area is:
$$A = l \times w$$
Using properties of operations, such as the distributive property, we can write an equivalent expression if $l$ and $w$ are expressed as sums or differences. For example, if $l = x + 3$ and $w = 2x$, then:
$$A = (x + 3)(2x)$$
Using distributive property:
$$A = x \times 2x + 3 \times 2x = 2x^2 + 6x$$
This is an equivalent expression for the area.
2. Problem 29: Jamie says $6x - 2x + 4$ and $4(x + 1)$ are not equivalent because one has a subtraction term and the other does not.
Let's simplify $6x - 2x + 4$:
$$6x - 2x + 4 = (6x - 2x) + 4 = 4x + 4$$
Now expand $4(x + 1)$:
$$4(x + 1) = 4x + 4$$
Both expressions simplify to $4x + 4$, so they are equivalent. Jamie's reasoning is incorrect because subtraction inside an expression can be combined and simplified to addition.
3. Problem 31: Chris says $4n - 2$ can be written as $2(2n - 1)$.
Let's expand $2(2n - 1)$:
$$2(2n - 1) = 2 \times 2n - 2 \times 1 = 4n - 2$$
This matches the original expression exactly, so Chris is correct.
Final answers:
- Problem 28: Area expression $A = l \times w$ and equivalent expression $A = 2x^2 + 6x$ if $l = x + 3$ and $w = 2x$.
- Problem 29: Expressions are equivalent.
- Problem 31: Expression can be factored as $2(2n - 1)$.
Algebraic Expressions 3Ad80B
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.