5) Выражением:
4 1/2 - ( 5 5/9 +3 1/3 - 2 1/6 +2 1/9)=
= 4 1/2 - (7 6/9 + 3 1/3 - 2 1/6 )=
= 4 1/2 - ( 7 12/18 + 3 6/18 - 2 3/18 )=
= 4 1/2 - 8 15/18 = - (8 15/18 - 4 9/18)=
=- - 3 6/18= -3 3/9
Если нужно по действиям:
4 1/2 - ( 5 5/9 +3 1/3 - 2 1/6 + 2 1/9 )=
1) 5 5/9 +3 1/3 = 5 5/9 + 3 3/9= 8 8/9
2) 8 8/9 - 2 1/6 = 8 16/18 - 2 3/18=6 13/18
3) 6 13/18 + 2 1/9 = 6 13/18 + 2 2/18 = 8 15/18
4) 4 1/2 - 8 15/18 = 4 9/18 - 8 15/18 = -3 6/18=-3 3/9
2) (-2/3+0,8+1/2) - (5/6-0,3)+0,4=
=(-2/3 +1,3) - ( 50/60 - 18/60)+0,4=
= ( 39/30 -20/30) - 32/60 +4/10=
= (19*2)/ (30*2) - 32/60 + 24/60=
= (38-32+24) /60= 30/60= 1/2=0,5
По действиям:
(-2/3 +0,8 +1/2) -(5/6-0,3) +0,4=0,5
1) -2/3 +0,8 = -2/3 + 8/10 = -20/30 + 24/30= 4/30 = 2/15
2) 2/15 +1/2 = 4/30+ 15/30=19/30
3) 5/6-0,3= 5/6 -3/10=50/60 -18/60= 32/60=16/30
4) 19/30-16/30=3/30=1/10=0,1
5) 0,1 +0,4 =0,5