1 + 5/21 + 2/15 = 1 + 5/21 + 2/15 = 1 + (515 + 221) / (21*15) = 1 + (75 + 42) / 315 = 1 + 117 / 315 = 315/315 + 117 / 315 = (315 + 117) / 315 = 432 / 315 = 24/35
1 + 5/21 + 2/15 = 1 + 5/21 + 2/15
= 1 + (515 + 221) / (21*15)
= 1 + (75 + 42) / 315
= 1 + 117 / 315
= 315/315 + 117 / 315
= (315 + 117) / 315
= 432 / 315
= 24/35