1.
(5/4 : 10/3 -1/3 xx6/5 ):(-2)
=(5/4xx3/10 -1/3 xx6/5 )xx(-1)/2
=(3/8-2/5 )xx(-1)/2
=(15/40-16/40)xx(-1)/2
=(-1)/40xx(-1)/2
=1/80
2.
(1/3 xx (-1)/2) - (1/2 - 1/3) + (1/4-1/5)
=-1/6- (3/6 - 2/6) + (5/20-4/20)
=-1/6- 1/6+1/20
=-(2)/6+1/20
=-(20)/60+3/60
=-17/60
4.
(5+ 1/3 - 1/7) - (2+1/3 +2/14)
=5+ 1/3 - 1/7-2-1/3-1/7
=(5-2)+ (1/3-1/3)+( - 1/7-1/7)
=3- 2/7
=19/7
6.
(3- 1/2 ) xx 1/25 + (4-1/3): 126/6
=(6/2- 1/2 ) xx 1/25 + (12/3-1/3):21
=5/2xx 1/25 + 11/3xx1/21
=1/10+11/63
=63/630+110/630
=173/630
