Question

А) (3/4 - 1/2)•5= ... б) (5/7+1/21):2= ...

Answer 1

А) (3/4 - 1/2)•5 =  1 1/4

1) 3/4 - 1/2 = 1/4

2)1/4 •5= 1 1/4

б) (5/7+1/21):2  = 8/21

1) 5/7+1/21 = 16/21

2)16/21 : 2 = 8/21

Answer 2

А) (3/4 - 1/2)•5=

First, we need to simplify the expression inside the parentheses by finding a common denominator:

3/4 - 1/2 = 6/8 - 4/8 = 2/8 = 1/4

Now we can substitute this value back into the original expression:

(1/4)•5 = 5/4

Therefore, (3/4 - 1/2)•5 = 5/4.

Б) (5/7+1/21):2=

First, we need to simplify the expression inside the parentheses by finding a common denominator:

5/7 + 1/21 = 15/21 + 1/21 = 16/21

Now we can divide this value by 2:

(16/21) ÷ 2 = 16/21 x 1/2 = 8/21

Therefore, (5/7+1/21):2 = 8/21.