a, 1727 + [ 6993 : 111 + ( 848 - 95 ) ] x 4 - 2
= 1727 + [ 63 + 753 ] x 4 - 2
= 1727 + 816 x 4 - 2
= 1727 + 3264 - 2
= 4991 - 2
= 4989
b, 75/100 + 18/21 + 19/32 + 1/4 + 3/21 + 13/32
= 75/100 + 1/4 + ( 18/21 + 3/21 ) + ( 19/32 + 13/32 )
= 75/100 + 25/100 + 21/21 + 32/32
= 100/100 + 1 + 1
= 1 + 1 + 1 = 3
c, 4 2/5 + 5 6/9 + 2 3/4 + 3/5 + 1/3 + 1/4
= ( 4 2/5 + 3/5 ) + ( 2 3/4 + 1/4 ) + 5 6/9 + 1/3
= 5 + 3 + 5 6/9 + 3/9
= 5 + 3 + 6
= 8 + 6 = 14
d, 3/4 + 25/36 - ( 4/9 + 13/18 + 1/72 )
= 27/36 + 25/36 - ( 32/72 + 52/72 + 1/72 )
= 52/36 - ( 84/72 + 1/72 )
= 52/36 - 85/72
= 104/72 - 85/72
= 19/72
