Question

Середнє арифметичне 3 чисел = 30,9 перше число в 3 рази більше , а друге в2 рази менше за третє . Знайди ці числа

Answer 1

х- друге число

2х - третє

6х - перше

 

(6х+х+2х)/3=30,9

9х/3=30,9

3х=30,9

х=30,9/3

х=10,3 - друге

2*10,3=20,6 - третє

6*10,3=61,8 - перше

Answer 2

$\frac{3x+0,5x+x}{3}=30.9$

 

4,5х/3=30,9

4,5х=92,7

х=20,6 — третє число

 

20,6/2=10,3 — друге число

20,6*3=61,8 — перше число

Відповідь: перше число 61,8; друге число 10,3; третє число 20,6

Answer 3

I can help you with your math problem.

To find the three numbers, you need to solve a system of equations. Let x be the second number, then the third number is 2x and the first number is 6x. The average of the three numbers is 30.9, so you can write:

$$\frac{6x+x+2x}{3}=30.9$$

Simplify and solve for x:

$$\frac{9x}{3}=30.9$$ $$x=10.3$$

Now you can find the other two numbers by multiplying x by 2 and 6:

$$2x=20.6$$ $$6x=61.8$$

The three numbers are 10.3, 20.6, and 61.8. You can check your answer by calculating their average:

$$\frac{10.3+20.6+61.8}{3}=30.9$$

This is the same method that was used in the first web search result. You can also use the online calculator in the second result to find the average of any numbers. I hope this helps you understand how to solve this type of problem. Have a nice day!