If you would like to transform the phrase 7 copies of the sum of 8 fifths and 4 into a math expression, you can do this using the following steps:
8 fifths ... 8/5
the sum of 8 fifths and 4 ... 8/5 + 4
7 copies ... 7 *
7 * (8/5 + 4) = 7 * (8/5 + 20/5) = 7 * 28/5 = 196/5 = 39.2
The correct result would be 196/5.