Question 232621
 2/5 + ? = 1
2/5 + ? = 5/5
? = 5/5 - 2/5
? = 3/5
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You could use x, or some other name
2/5 + x = 1
1 = 5/5
2/5 + x = 5/5
x = 5/5 - 2/5
x = 3/5