So first find the factors of the denomenatores
14=2 times 7
7=7
21=7 times 3
common one would be having at least one 2, one 7, and one 3
find what numbers can be made by all of them
2 times 7 times 3
2 times 7
7
7 times 3
they are all in it
2 times 3 time s7=42
common denoomenator is 42
1) a=16
a is 16 because 16/4 is 4. 2 plus 4 is 6
Answer:
10.5 hours
Step-by-step explanation:
42/4 = 10.5