Answer:
n = 1
Step-by-step explanation:
[tex]\frac{20}{n} +10 = \frac{10}{n} +20\\\frac{20}{n} -\frac{10}{n} = 20 - 10\\\frac{10}{n} = 10\\n = \frac{10}{10} =1\\[/tex]
[tex]\frac{20}{1} +10 = \frac{10}{1} + 20\\30 = 30[/tex]