Question

4-(4 21/40-5,25) : 7/20​

Answer 1

Ответ:

Пошаговое объяснение:

Answer 2

To simplify the expression, let's first convert the mixed number into an improper fraction:

4 21/40 = (4 * 40 + 21) / 40 = 161/40

Now we can substitute this value into the expression:

4 - (161/40 - 5.25) : 7/20

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

161/40 - 5.25 = (161/40) - (5.25 * 40/40) = 161/40 - 210/40 = (161 - 210) / 40 = -49/40

Now the expression becomes:

4 - (-49/40) : 7/20

To divide fractions, we invert the second fraction and multiply:

4 - (-49/40) * (20/7)

Now multiply the fractions:

4 - (-49/40) * (20/7) = 4 - (-980/280) = 4 + 980/280

To add fractions, we need to find a common denominator:

The common denominator of 280 and 1 is 280.

4 + 980/280 = (4 * 280/280) + 980/280 = 1120/280 + 980/280 = (1120 + 980) / 280 = 2100/280

Now we can simplify the fraction:

2100/280 = 21/28

Therefore, the simplified expression is 21/28.