Solve linear equation: n/2 - 3n/4 + 5n/6 = 21

Given equation is n/2 - 3n/4 + 5n/6 = 21
LCM of 2, 4 and 6 is 12
=> 6n - 9n + 10n/12 = 21
=> 7n/12 = 21
Multiply both sides by 12
7n/12 × 12 = 21 × 12
7n = 252
n = 252/7
∴n = 36