4/5 = 1/2 +1/5 +1/10
3/8 = 1/4 +1/8
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It isn't clear whether you want the second decomposition to be using unit fractions, or what other restrictions may apply. It also is not clear what sort of equation is intended. Perhaps your text has an example for guidance.
4/5 = 1/2 +1/4 +1/20
3/8 = 1/3 +1/24