Question

А) (х-3,8) : 3х=0,4 : 5 б) 6,8 : (х+8) = 2 : х

Answer 1

Ответ:

Пошаговое объяснение:

это пропорция, поэтому произведение крайних членов = произведению средних членов:

а) 5*(х-3,8) = 0,4*3х

 5х -  19 = 1,2х

5х-1,2х = 19                            б)   6,8*х = 2*(х+8)

3,8х = 19                                       6,8х = 2х+16

х=19 / 3,8                                      6,8х-2х=16

х= 5                                               4,8х = 16

                                                      х= 16/4,8

                                                     х=160/48 = 80/24 = 20/6 = 3 2/6 = 3 1/3

Answer 2

а) To solve the equation (х-3,8) : 3х=0,4 : 5, we can start by simplifying the left-hand side:

(х-3,8) : 3х = (х-3,8) / 3х

To simplify the right-hand side, we can rewrite 0.4 and 5 as fractions with a common denominator of 10:

0.4 = 4/10 5 = 50/10

Now we can substitute these values into the equation:

(х-3,8) / 3х = 4/10 : 50/10

Simplifying the right-hand side:

4/10 : 50/10 = 4/10 * 10/50 = 4/50 = 2/25

Substituting this value back into the equation:

(х-3,8) / 3х = 2/25

Now we can cross-multiply to get rid of the fractions:

25(х-3,8) = 6х

Expanding the brackets:

25х - 95 = 6х

Simplifying:

19х = 95

Dividing both sides by 19:

х = 5

Therefore, the solution to the equation is х = 5.

б) To solve the equation 6,8 : (х+8) = 2 : х, we can start by simplifying the left-hand side:

6,8 / (х+8)

To simplify the right-hand side, we can cross-multiply to get rid of the fractions:

2(х+8) = 6,8х

Expanding the brackets:

2х + 16 = 6,8х

Subtracting 2х from both sides:

16 = 4,8х

Dividing both sides by 4,8:

х = 16/4,8

Simplifying:

х = 10/3

Therefore, the solution to the equation is х = 10/3 or 3.33 (rounded to two decimal places).