Question

0,6х(4y-18)-0,4х(5-7y) При y=2 4/13

Answer 1

Ответ:

Объяснение:

0,6х(4y-18)-0,4х(5-7y)=2.4у-10.8-2+2.8у=5.2у-12.8

5.2*2 4/13=26/5*30/13=12

12-12.8=-0.8

Answer 2

To evaluate the given expression when y = 2 4/13, we substitute this value into the expression:

0.6 * (4(2 4/13) - 18) - 0.4 * (5 - 7(2 4/13))

First, let's simplify the inner expressions:

4(2 4/13) = 4 * (2 + 4/13) = 8 + (4/13) * 4 = 8 + 16/13 = 8 16/13

7(2 4/13) = 7 * (2 + 4/13) = 14 + (4/13) * 7 = 14 + 28/13 = 14 28/13

Now, substituting these values back into the expression:

0.6 * (8 16/13 - 18) - 0.4 * (5 - 14 28/13)

To simplify further, we convert all mixed numbers into improper fractions:

8 16/13 = (8 * 13 + 16) / 13 = 120/13

14 28/13 = (14 * 13 + 28) / 13 = 210/13

Now we can rewrite the expression:

0.6 * (120/13 - 18) - 0.4 * (5 - 210/13)

To simplify, we perform the operations within parentheses:

0.6 * (120/13 - 234/13) - 0.4 * (65/13 - 210/13)

Simplifying the fractions:

0.6 * (-114/13) - 0.4 * (-145/13)

Multiplying:

-68.4/13 + 58/13

Combining like terms:

(-68.4 + 58)/13

Simplifying further:

-10.4/13

Therefore, when y = 2 4/13, the value of the expression 0.6x(4y-18) - 0.4x(5-7y) is -10.4/13.