(12/25 + 8/25 - 4/17) * 25 = (20/25 - 4/17) * 25
= (4/5 - 4/17) * 25 = ((68 - 20) / 85) * 25 = (48/85) * 25
= (48 * 25) / 85 = (48 * 5) / 17 = 240/17