Ella practices piano for 45 minutes.
She spends m minutes longer working on homework
From the question, The total minutes Ella spend on piano is 45 minutes
If she spend m minutes longer
In mathematics, more in word problem means addition
Total minutes spend on her home work is
m + 45
Let T be the total time she spendon her homework
T = Additional m minutes + 45 minutes spend on her piano
T = m + 45
The answer is T = m + 45