Question

(0,8+1/20)÷(21 1/3-19 1/15)-4,1​

Answer 1

Ответ:

(0,8 + 1/20)÷(21 1/3-19 1/15) = 8/10 + 1/20 ÷ 2 4/15 = 17/20 ÷ 34/15 = 17/20 * 15/34 = 3/8

Answer 2

To simplify the expression (0,8 + 1/20) ÷ (21 1/3 - 19 1/15) - 4.1, follow these steps:

Step 1: Convert the mixed numbers to improper fractions.

21 1/3 = 64/3 19 1/15 = 286/15

Step 2: Perform the operations inside the parentheses first.

0.8 + 1/20 = 16/20 + 1/20 = 17/20

Now, the expression becomes:

(17/20) ÷ (64/3 - 286/15) - 4.1

Step 3: Subtract the fractions in the denominator:

64/3 - 286/15

To subtract fractions, you need a common denominator. The least common multiple (LCM) of 3 and 15 is 15. So, you need to convert 64/3 to an equivalent fraction with a denominator of 15:

(64/3) * (5/5) = 320/15

Now, subtract:

320/15 - 286/15 = (320 - 286) / 15 = 34/15

So, the expression becomes:

(17/20) ÷ (34/15) - 4.1

Step 4: Divide the fractions:

(17/20) ÷ (34/15)

To divide fractions, you can multiply by the reciprocal of the second fraction:

(17/20) * (15/34)

Now, multiply the numerators together and the denominators together:

(17 * 15) / (20 * 34) = 255/680

Step 5: Subtract 4.1 from the fraction:

255/680 - 4.1

To subtract a fraction from a decimal, you need to convert the decimal to a fraction. 4.1 is the same as 41/10.

Now, subtract:

(255/680) - (41/10)

To subtract fractions with different denominators, find a common denominator. The LCM of 680 and 10 is 680, so you need to adjust the second fraction:

(255/680) - (41/10) * (68/68) = (255/680) - (2780/680)

Now, subtract:

(255 - 2780) / 680 = (-2525/680)

Step 6: Simplify the resulting fraction:

-2525/680 = -505/136

So, the simplified expression is:

-505/136