Respuesta :

·1/5n becomes 4/20n
·Leave 3/4 alone
·7/10n becomes 14/20n
·Combine like terms: 14/20n + 4/20n = 18/20n
·Simplify 18/20 to 9/10
·Final Answer : 9/10 - 3/4

Hope this helps you out in future problems!