3 over 4 plus 1 over 5 times n equals 1 over 2
(3 / 4) + (1 /5)n = (1/2) subtract 3/4 from both sides
(1 / 5)n = 1/2 - 3/4 → 1/2 - 3/4 = 2/4 - 3/4 = -1/4
(1/5)n = -1/4 multily both sides by 5
n = -5/4
