An equation is formed of two equal expressions. The cost of a new book is $7.43, while the cost of an old book is $8.86.
<h3>What is an equation?</h3>
An equation is formed when two equal expressions are equated together with the help of an equal sign '='.
Given the cost of 14 used books is $124. Therefore, the cost of a single used book is,
Cost of single used book(u) = 124/14 = $8.86
Also, the cost of 12 used books and 4 new books is $136. Therefore, the equation can be written as,
12u + 4n = 136
12(8.85) + 4n = 136
106.2 + 4n = 136
n = $7.43
Hence, the cost of a new book is $7.43, while the cost of an old book is $8.86.
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