Question

Решите пропорции 3x+4/28=1/4 3,8/1,9=18/2x+7 2/x-1=1/5 3/4=x-4/8

Answer 1

3x+4/28=1/4
4*(3x+4)=28*1
12x+16=28
12x=28-16
12x=12
x=12:12
x=1

3,8/1,9=18/2x+7
3,8*(2x+7)=18*1,9
7,6x+26,6=34,2
7,6x=34,2-26,6
7,6x=7,6
x=7,6:7,6
x=1

2/x-1=1/5
x-1=2*5
x-1=10
x=10+1
x=11


3/4=x-4/8
4*(x-4)=8*3
4x-16=24
4x=24+16
4x=40
x=40:4
x=10

Answer 2

1. 3x+4/28=1/4

Multiplying both sides by 28, we get:

3x+4 = 7

Subtracting 4 from both sides, we get:

3x = 3

Dividing both sides by 3, we get:

x = 1

Therefore, the solution is x = 1.

2. 3.8/1.9 = 18/2x+7

Multiplying both sides by (2x+7), we get:

3.8(2x+7) = 18(1.9)

Expanding the left side and simplifying, we get:

7.6x + 26.6 = 34.2

Subtracting 26.6 from both sides, we get:

7.6x = 7.6

Dividing both sides by 7.6, we get:

x = 1

Therefore, the solution is x = 1.

3. 2/x-1 = 1/5

Multiplying both sides by (x-1), we get:

2 = (x-1)/5

Multiplying both sides by 5, we get:

10 = x-1

Adding 1 to both sides, we get:

x = 11

Therefore, the solution is x = 11.

4. 3/4 = x-4/8

Multiplying both sides by 8, we get:

6 = 2x-4

Adding 4 to both sides, we get:

10 = 2x

Dividing both sides by 2, we get:

x = 5

Therefore, the solution is x = 5.