Question

(2,25-1,25•(2/7+1 1/21)):0,7-0,2

Answer 1

= решение = решение = решение = решение = решение =

Answer 2

(2,25-1,25•(2/7+1 1/21)):0,7-0,2=29/105

2/7+1 1/21=2/7+22/21=(2*3+22)/21=28/21=4/3

1 1/4*4/3=(5*4)/4*3=5/3

2 1/4-5/3=9/4-5/3=(9*3-5*4)/21=7/21=1/3

1/3:7/10=1*10/3*7=10/21

10/21-1/5=(10*5-1*21)/105=29/105

Answer 3

Let's solve the expression step by step:

(2.25 - 1.25 * (2/7 + 1 1/21)) ÷ (0.7 - 0.2)

First, let's simplify the innermost parentheses:

2/7 + 1 1/21 = 2/7 + 1 + 1/21 = (2/7 + 21/21 + 1/21) = (2/7 + 22/21)

Next, find a common denominator for 7 and 21, which is 21:

(2/7 + 22/21) = (6/21 + 22/21) = 28/21

Now, the expression becomes:

(2.25 - 1.25 * (28/21)) ÷ (0.7 - 0.2)

Next, calculate the multiplication:

1.25 * (28/21) = 1.25 * (4/3) = 5/3

Now, the expression becomes:

(2.25 - 5/3) ÷ (0.7 - 0.2)

Next, find a common denominator for 3 and 3:

2.25 - 5/3 = 2.25 - (5/3 * 3/3) = 2.25 - 15/9

Now, the expression becomes:

(2.25 - 15/9) ÷ (0.7 - 0.2)

Calculate the subtraction:

2.25 - 15/9 = (18/9 - 15/9) = 3/9 = 1/3

Now, the expression becomes:

(1/3) ÷ (0.7 - 0.2)

Calculate the subtraction:

0.7 - 0.2 = 0.5

Now, the expression becomes:

(1/3) ÷ 0.5

To divide by a fraction, we multiply by its reciprocal:

(1/3) ÷ 0.5 = (1/3) * (1/0.5) = 1/3 * 2 = 2/3

So, the final result is 2/3.