Question

Lawrence just added 15 more songs to his MP3 player, making the total number of songs more than 84. Draw a number line that represents the original number of songs he had on his MP3 player.

Short answer

Number line representing original number of songs on MP3 player

Step-by-step solution

Step 1. Write a given information in terms of inequality.

Let n be the number of original songs on the MP3 player, such that,

$n+15>84$

Step 2. Write subtraction property of inequalities.

For all numbers a,b and c, if $a>b$, then $a-c>b-c$.

Step 3. Apply subtraction property of inequalities.

Subtract 15 from both the sides of $n+15>84$.

$$\begin{gathered} n+15-15>84-15 \\ n>69 \end{gathered}$$

Therefore, there were originally more than 69 songs on his MP3 player.

Step 4. Graph the solution.

Graph the obtained solution on number line.