Answer:
$138
Explanation:
We can first turn the words into a mathematical equation by substituting words with the information we have:
Total earning - ( Price of three books)
$180 - (Price of one book x 3)
$180 - ($14 x 3)
Finally, after we have created the mathematical equation, we solve it!
$180 - ($14 x 3)
$180 - $42
$138