Решите a) (5/7+1/21): 2 b) (7/10-1/5): 3 c) (1/4-1/12)*5 d) (1/4+1/6): 10 e) (5/6-1/4): 7 с решением

A) 0.7+0.4=1.1/21=0.05
b)0.7-0.2=0.5/3=0.16
c)0.25-0.08=0.17*5=0.85
d) 0.25-0.16/10=0.016
e) 0.8-0.25=0.55/7=0.07

1) 16/21:2=8/21
2)5/10:3=5/30=1/6
3)2/12*5=10/12=5/6

(1       1)

+ : 10=

4        6

е)7/12-4/12=3/12:7=4/84

 

1/4 + 1/6=3/12 +2/12= 5/12

5        10       5       1        1

:  = х  =

12       1        12      10    24