1) 4 ( 3/4 ) + 1 ( 2/3 ) = 19/4 + 5/3 = 57/12 + 20/12 = 77/12
2) 77/12 * 16/21 = 44/9
3) 1/4 * 4 ( 3/4 ) = 1/4 * 19/4 = 19/16
4) 19/16 * 16/57 = 19/57
5) 2/27 * 4 ( 1/2 ) = 2/27 * 9/2 = 9/27
6) 19/57 + 44/9 + 9/27 = 171/513 + 2508/513 + 171/513 = 2850/513 =
= 5 ( 285/513 )