Solve.
The perimeter of a rectangular calculator is $36 \mathrm{~cm}$. The length is $4 \mathrm{~cm}$ greater than the width. Find the width and the length.

Solve. Write the answer in both set-builder notation and interval notation. \

$$4(2 n-3) \leq 2(5 n-8)$$

Convert to decimal notation. \

$$6.25 \%$$

Use an inequality and the five-step process to solve each problem.
RJ's Plumbing and Heating charges $\$ 55$ plus $\$ 40$ per hour for emergency service. Gary remembers being billed over $\$ 150$ for an emergency call. How long was RJ's there?

Solve each formula for the indicated letter.
$E=m c^2$, for $c^2$ (A relativity formula from physics)

Solve. Even though you might find the answer quickly in another way, use the five-step process in order to build the skill of problem solving.
In $2010$, approximately $294$ billion e-mail messages were sent each day. The number of spam messages was about nine times the number of nonspam messages. How many of each type of message were sent each day in $2010$?

Graph on the number line. \

$$-5 \leq x<2$$

Solve. Label any contradictions or identities. \

$$3(x-4)+2=x+2(x-5)$$

Solve. Don't forget to check! \

$$x-18=23$$

Solve and check. \

$$-6 z-18=-132$$

Graph on the number line. \

$$-2 \leq x \leq 2$$

Translate to an inequality.
The cost of gasoline was at most $\$ 4$ per gallon.

Solve. Label any contradictions or identities. \

$$8(x-2)=4(x-4)$$

Solve. Don't forget to check! \

$$-5=x+8$$