Add and subtract rational expressions with relatively prime denominators by manipulating them to have the same denominators.

Problem

Tom and Li-Min were each asked to perform the following operation:
start fraction, 7, m, minus, 4, divided by, m, plus, 9, end fraction, plus, start fraction, 8, divided by, 7, m, start superscript, 5, end superscript, end fraction
Their answers are shown below:
TomLi-Min
start fraction, 49, m, start superscript, 6, end superscript, minus, 28, m, start superscript, 5, end superscript, plus, 8, m, plus, 72, divided by, 7, m, start superscript, 6, end superscript, plus, 63, m, start superscript, 5, end superscript, end fractionstart fraction, 29, m, start superscript, 2, end superscript, plus, 72, divided by, 70, m, start superscript, 11, end superscript, end fraction
Is either of the students correct?
Please choose from one of the following options.