Question

А)(9-2 2/3*2 1/7)*21/46. Б) (4/25+7/15)*75​

Answer 1

Ответ:

$1) \frac{3}{2} 2)47$

Answer 2

To solve these expressions, let's take them one at a time:

A) (9 - 2 2/3 * 2 1/7) * 21/46:

First, let's simplify the expression within the parentheses:

2 2/3 can be converted to an improper fraction as follows: 2 * 3 + 2 = 6 + 2 = 8 8/3

2 1/7 can be converted to an improper fraction as follows: 2 * 7 + 1 = 14 + 1 = 15 15/7

Now we can rewrite the expression as: (9 - 8/3 * 15/7) * 21/46

Next, let's perform the multiplication within the parentheses: 8/3 * 15/7 = (8 * 15) / (3 * 7) = 120/21 = 40/7

Now we can rewrite the expression as: (9 - 40/7) * 21/46

To simplify further, let's find a common denominator for the subtraction: 9 can be written as 9/1

Now the expression becomes: (9/1 - 40/7) * 21/46

To subtract the fractions, we need a common denominator of 7: (9/1 * 7/7 - 40/7) * 21/46 = (63/7 - 40/7) * 21/46 = 23/7 * 21/46

Multiplying the numerators gives us: 23 * 21 = 483

And multiplying the denominators gives us: 7 * 46 = 322

Therefore, the expression simplifies to: 483/322

B) (4/25 + 7/15) * 75:

To add the fractions, we need a common denominator of 75: 4/25 can be written as 4/25 * 3/3 = 12/75 7/15 can be written as 7/15 * 5/5 = 35/75

Now the expression becomes: (12/75 + 35/75) * 75

Adding the fractions gives us: 47/75 * 75

The 75s cancel out, leaving us with: 47/1 = 47

Therefore, the expression simplifies to: 47