Let's forget the m's for now.
Step 1 Anaylze the Problem - Our equation would be 10 + 8 = 7 +17.
Step 2 Work out the problems - 10 + 8 = 18 and 7 + 17 = 24.
Step 3 Ask yourself - Is 18 and 24 equal to each other? (Meaning are they the same numbers?)
After finding your answers, just plug in the m that we took out in the beginning.
Have an awesome day! -Wajiha