4 2 per 5+7 1 per2-6 3 per4: NB:sorry ngak bisa pake per hehe

4 2/5 = 22/5 = 88/20
7 1/2 = 15/2 = 150/20
6 3/4 = 27/4 = 135/20

= 4 2/5 + 7 1/2 - 6 3/4
= 88/20 + 150/20 - 135/20
= 103/20
= 5 3/20

4 2/5 + 7 1/2 - 6 3/4
= (4 + 7 - 6) 2/5 + 1/2 - 3/4
= (4 + 7 - 6) 8/20 + 10/20 - 15/20
= 5 3/20