Express each product in simplest form

1.) 4 / 5 . 15 / 28

2.) 3 / a . 7 / b

3.) a / b . b / c . c / a^2

Please show you're solution how was it done.

1. (4/5) (15/28) = (4/5) [ (5 * 3) / (7 * 4) ]
= 3/7

2. (3/a) (7/b) = 21 / ab

3. (a/b) (b/c) (c/a^2) = (abc / a^2bc) . .cancel abc on the numerator
= 1 / a

4 15 = 60/10 = 6/2 = 3
5 28 = 140/10 =14/2 = 7 Answer 3/7

3 7 = 21
a b = ab you cant simplify so your answer would be 21/ab

a b c abc take away the abc 1
b c a^2 a^2b^2c abc