Răspuns:
Explicație pas cu pas:
1).
a). [3/4+2/3:(3/4-1/2)]*6/41=
[3/4+2/3:(3/4-2/4)]*6/41=
(3/4+2/3:1/4)*6/41=
(3/4+2/3*4/1)*6/41=
(3/4+8/3)*6/41=
(9/12+32/12)*6/41=
41/12*6/41=
1/2
b). [7/5:14/15+3/2:(9/4-11/2)]*2/7=
[7/5:14/15+3/2*(9/4-3/2)]*2/7=
[7/5:14/15+3/2*(9/4-6/4)]*2/7=
(7/5:14/15+3/2*3/4)*2/7=
(7/5*15/14+3/2*3/4)*2/7=
(3/2+9/8)*2/7=
(12/8+9/8)*2/7=
21/8*2/7=3/4
c).nu am invatat cu perioada
d). [4+62/3-21/4*(2/3-2/9)]:45/6+29/4=
[4+20/3-9/4*(6/9-2/9)]:29/6+29/4=
(4+20/3-9/4*4/9):29/6+29/4=
(4+20/3-1):29/6+29/4=
(12/3+20/3-3/3):29/6+29/4=
29/3:29/6+29/4=
29/3*6/29+29/4=
2+29/4=
8/4+29/4=
37/4
2). a). 25/2*9=225/2 b). 28/13:7=28/13*1/1=4/13
3).7x+4y x=2/3 y=9/5
7*2/3+4*9/5=23/3+29/5=115/15+87/15=202/15
4). 32/5*21/4=17/5*9/4=153/20
5).
a). (x+2 8/15)*3/2=5 1/4
(x+38/15)*3/2=21/4
(x+38/15)=21/4:3/2
(x+38/15)=21/4*2/3
x+38/15=7/2
x=7/2-38/15
x=105/15-76/15
x=29/15
b). 109/50:y=109/1000 y=109/1000:109/50 y=109/1000*50/109 y=1/20
6). 54 17/20=1097/20
1 1/5=6/5
2 3/10=23/10
6/5*15=18m pentru 15 perechi de pantaloni
23/10*8=92/5 m pentru 8 costume
1097/20-(18+92/5)=
1097/20-(90/5+92/5)=
1097/20-182/5=
1097/20-728/20=
369/20 m stofa raman
sper sa fie bine
