topic badge

3.03 Rewriting expressions to understand relationships

Interactive practice questions

In a particular year, Re-source Waste Recovery produces sewage treatment plants at a cost of $\$u$$u per plant. Re-source Waste Recovery also pays a fee of $\$b$$b per year for its use of the production facilities.

a

Using only addition, write an expression that represents the total production cost from $1$1 year if there are $3$3 sewage treatment plants produced in that year.

b

Which of the following expressions is also equivalent to the production cost in that year?

$3u+b$3u+b

A

$3\left(u+b\right)$3(u+b)

B

$b+b+b+u$b+b+b+u

C

$bu$bu

D
Medium
1min

A clothing store receives a shipment of jackets and skirts. The jackets come in blue boxes containing $6$6 jackets each, while the skirts come in red boxes containing $5$5 skirts each. In this shipment, there are $x$x blue boxes and $y$y red boxes.

Medium
1min

Consider the case when $n$n is even and $m$m is odd.

Medium
2min

Xavier travels to a foreign country, where the value of currency is described in terms of the values ‘$x$x’ and ‘$y$y’. When Xavier arrives, he has plenty of coins worth $2y$2y and plenty of notes worth $x+y$x+y, but none of the several other types of coins or notes.

Hard
3min
Sign up to access Practice Questions
Get full access to our content with a Mathspace account

Outcomes

7.EE.A.2

Rewrite and connect equivalent expressions in different forms in a contextual problem to provide multiple ways of interpreting the problem and investigating how the quantities in it are related. For example, shoes are on sale at a 25% discount. How is the discounted price P related to the original cost C of the shoes? C – 0.25C = P. In other words, P is 75% of the original cost since C – 0.25C can be written as 0.75C.

What is Mathspace

About Mathspace