1) 9/c + 5/c = (9 + 5) / c = 14/c
2) a/c + 4/c = (a + 4) / c
3) a/c + b/3c = 3a/3c + b/3c = (3a + b) / 3c
1) 9/c + 5/c = (9 + 5) / c = 14/c
2) a/c + 4/c = (a + 4) / c
3) a/c + b/3c = 3a/3c + b/3c = (3a + b) / 3c