Question

1) (3/7 - 16/21) * 2 1/7 + (11/15 +0,3) :12 2/5 2) (3/8-7/12)*3,6+(5/18+2/27):1 11/27 3) (5/9-11/12)*3 9/13+(0,3125+ 5/24) *4 4/5 4) (3/4-4/5)*7,8+(2/3+4/7)*7/13 Помогите пожалуйста решить, желательно с обьяснениями)

Answer 1

№1
1)    3\7-16\21=3*3\21-16\21=-7\21=-1\3
    -1\3*2 1\7=-1\3*15\7=-5\7
11\15+3\10=11*2\30+3*3\30=31\30
31\30:12 2\5=31\30*5\62=1\12
-5\7+1\12=-5*12\84+7/84=-53\84

2)3\8-7\12=3*3\24-7*2\24=-5\24
  -5\24*3 6\10=-3\4
5\18+2\27=5*3\54+2*2\54=19\54
19\54:1 11\27=19\54*27\38=1\4
-3\4+1\4=-2\4=-1\2

3)5\9-11\12=5*4\36-11*3\36=-13\36
-13\36*3 9\13=-13\36*48\13=-4\3
0.3125+5\24=5\16+5\24=5*4\48+5*2\48=30\48=5\8
5\8*4 4\5=5\8*24\5=3
-13\36+3=2 23\36=2 1\2

4)3\4-4\5=3*5\20-4*4\20=-1\20
-1\20*7.8=-0.05*7.8=-0.39
2\3+4\7=2*7\21+4*3\21=26\21
26\21*7\13=2\3
-0.39+2\3=-39*3\100+2*100\300=83\300

Answer 2

1. (3/7 - 16/21) * 2 1/7 + (11/15 +0.3) :12 2/5

First, we can simplify the terms inside the parentheses of the second part of the expression:

(11/15 +0.3) = 11/15 + 3/10 = (22/30 + 9/30) = 31/30

Next, we can convert the mixed number 2 1/7 to an improper fraction:

2 1/7 = 15/7

Now we can substitute the simplified expressions into the original equation:

(3/7 - 16/21) * 15/7 + 31/30 : 12 2/5

To simplify the first part of the expression, we need to find a common denominator for 7 and 21, which is 21:

(3/7 - 16/21) = (9/21 - 16/21) = -7/21

Substituting this value back into the expression gives:

-7/21 * 15/7 + 31/30 : 12 2/5

We can simplify the first part of the expression:

-7/21 * 15/7 = -15/21 = -5/7

Substituting this value back into the expression gives:

-5/7 + 31/30 : 12 2/5

To simplify the second part of the expression, we need to convert the mixed number 12 2/5 to an improper fraction:

12 2/5 = 62/5

Now we can substitute the values and simplify the expression:

-5/7 + 31/30 ÷ 62/5

We can simplify the division first:

31/30 ÷ 62/5 = 31/30 * 5/62 = 1/12

Substituting this value back into the expression gives:

-5/7 + 1/12

To add these fractions, we need to find a common denominator, which is 84:

-5/7 * 12/12 + 1/12 * 7/7 = -60/84 + 7/84 = -53/84

Therefore, the final answer is:

-53/84

2. (3/8 - 7/12) * 3.6 + (5/18 + 2/27) : 1 11/27

To simplify the first part of the expression, we need to find a common denominator for 8 and 12, which is 24:

(3/8 - 7/12) = (9/24 - 14/24) = -5/24

Substituting this value back into the expression gives:

-5/24 * 3.6 + (5/18 + 2/27) : 1 11/27

We can simplify the first part of the expression:

-5/24 * 3.6 = -9/4 * 1/10 = -9/40

Substituting this value back into the expression gives:

-9/40 + (5/18 + 2/27) : 1 11/27

To simplify the second part of the expression, we need to convert the mixed number 1 11/27 to an improper fraction:

1 11/27 = 38/27

Now we can substitute the values and simplify the expression:

-9/40 + (5/18 + 2/27) ÷ 38/27

We can simplify the division first:

(