a,S= (-2/3 + 1) – (7/5 – 0,2 ) + (7/5 – 0,2 )
b,S= 0,25 – (-3/4) – [-7/3 + (9/2)] – 5/6
c, S= [1-(2/5 – 4/3) ] – [(0,8 – 1) – (1,4 + 2 )
a,S= (-2/3 + 1) – (7/5 – 0,2 ) + (7/5 – 0,2 )
b,S= 0,25 – (-3/4) – [-7/3 + (9/2)] – 5/6
c, S= [1-(2/5 – 4/3) ] – [(0,8 – 1) – (1,4 + 2 )
a,S= (-2/3 + 1) – (7/5 – 0,2 ) + (7/5 – 0,2 )
S= -2/3 + 1 – 7/5 + 0,2 +7/5 – 0,2
S =-2/3 + 1
b,S= 0,25 – (-3/4) – [-7/3 + (9/2)] – 5/6
S = 0,25 + 3/4 + 7/3 – 9/2 – 5/6
S = ( 0,25 + 3/4) + (7/3 – 5/6) – 9/2
S = 1,5 – 4,5 = -3
c, S= [1-(2/5 – 4/3) ] – [(0,8 – 1) – (1,4 + 2 )
S=1 – (- 14 / 15) – 0,8 + 1 – 1,4 – 2
S = 29/15 – 0,8 + 1 – 1,4 – 2
S = 29/15 – 16 / 5
S = -29/48