Răspuns:
a)
(12/25+3/5): 9/35=
(12/25+15/25)× 35/9=
27/25×35/9=
21/5
b)
(11/8+1/6) :37/3=
(33/24+4/24)×3/37=
37/24×3/37=
1/8
c)
(2 1/6-7/9) :5/9=
(2×6/6+1/6- 7/9) ×9/5=
(13/6-7/9)×9/5=
(39/18-14/18)×9/5=
25/18×9/5=
5/2
d)
(2 1/2+5 1/6) :7 2/3=
(2×2/2+1/2 + 5×6/6+1/6): 7×3/3+2/3=
(5/2+31/6) : 23/3=
(15/6+31/6)× 3/23=
46/6× 3/23=
2/2=
1
8)a)(2 1/10)/3/5=
(2×10/10+1/10)/ 3/5=
21/10× 5/3=
7/2
b) 1/9 / 3/7=
1/9×7/3=
7/27
c) 14/( 3 1/2)=
14/(3×2/2+1/2)=
14/ 7/2=
14×2/7=
28/7=
4
d) (5/7)/(15/42)=
5/7 × 42/15=
6/3=
2
e)
3 1/7 / 1 1/21=
(3×7/7+1/7) / (21/21+1/21)=
22/7 / 22/21=
22/7× 21/22=
1/3
g)
(1 2/3) / (4 1/6) =
(3/3+2/3)/ 4×6/6+1/6=
5/3 / 25/6=
5/3× 6/25=
2/5
h)
21/125 / 14/5=
21/125 × 5/14=
3/10
i)
2/ (6/9)=
2×9/6=
18/6=
3
j) (2/6) /9=
2×1 / 9×6=
1/27
k)
(3 5/6) / (1 11/12)=
(3×6/6+5/6) / (12/12+11/12)=
(23/6) / (23/12)=
23/6×12/23=
(23 ×12)/( 6×23)=
2
Explicație pas cu pas:
