Answer
$= \frac{41n}{20}$
Work Step by Step
1) Find a common denominator in Step #2: multiply the first fraction by $20$, the second fraction by $5$, the third fraction by $20$, and the fourth fraction by $4$ to obtain a common denominator of $20$
$n - \frac{3}{4}n + 2n - \frac{1}{5}n$
$= \frac{n}{1} - \frac{3}{4}n + \frac{2n}{1} - \frac{1}{5}n$ (Rewrite the expression with fractions)
$= \frac{n(20)}{20} - \frac{3n(5)}{20} + \frac{2n(20)}{20} - \frac{n(4)}{20}$
$= \frac{20n}{20} - \frac{15n}{20} + \frac{40n}{20} - \frac{4n}{20}$
$= \frac{20n-15n+40n-4n}{20}$
$= \frac{5n+40n-4n}{20}$
$= \frac{45n-4n}{20}$
$= \frac{41n}{20}$
