Question

7-3x=30-5x 0,9x-7,4=-0,4x+4,35•(x-4)=x+8(7x:9)-(11x-7)=8​

Answer 1

-3х+5х=30-7
2х=23
х= 11,5

0,9х+0,4х=4,3+7,4
1,3х=11,7
х=9

5х-20=х+8
5х-х=8+20
4х=28
х=7


(7х:9)-11х+7=8
прирівняти до нуля і розв’язати

Answer 2

To solve each of these equations, we'll isolate the variable x step by step. Let's work through them one by one:

1. 7 - 3x = 30 - 5x

First, let's get the variables on one side and constants on the other side:

Add 5x to both sides: 7 - 3x + 5x = 30 - 5x + 5x

This simplifies to: 7 + 2x = 30

Now, subtract 7 from both sides: 7 + 2x - 7 = 30 - 7

Simplify further: 2x = 23

Finally, divide by 2 to isolate x: (2x)/2 = 23/2

x = 23/2

So, the solution to this equation is x = 23/2 or 11.5.

2. 0.9x - 7.4 = -0.4x + 4.35

First, let's get all the x terms on one side and constants on the other side:

Add 0.4x to both sides: 0.9x - 7.4 + 0.4x = -0.4x + 0.4x + 4.35

Simplify: 1.3x - 7.4 = 4.35

Now, add 7.4 to both sides: 1.3x - 7.4 + 7.4 = 4.35 + 7.4

Simplify further: 1.3x = 11.75

Finally, divide by 1.3 to isolate x: (1.3x)/1.3 = 11.75/1.3

x ≈ 9.0385 (rounded to four decimal places)

So, the solution to this equation is approximately x ≈ 9.0385.

3. 4.35 * (x - 4) = x + 8(7x/9) - (11x - 7) = 8

First, simplify each part of the equation:

4.35 * (x - 4) = x + (56x/9) - (11x - 7) = 8

Now, distribute 4.35 on the left side of the equation:

4.35x - 17.4 = x + (56x/9) - (11x - 7) = 8

Next, simplify the fractions by finding a common denominator (9) for the terms on the right side:

(56x/9) - (11x - 7) = 8

Now, add (11x - 7) to both sides:

4.35x - 17.4 + (11x - 7) = 8 + (11x - 7)

Combine like terms:

15.35x - 24.4 = 8 + 11x - 7

Now, let's isolate the x terms on one side and constants on the other side:

15.35x - 11x = 8 + 7 + 24.4

Combine like terms:

4.35x = 39.4

Finally, divide by 4.35 to isolate x:

(4.35x)/4.35 = 39.4/4.35

x ≈ 9.0345 (rounded to four decimal places)

So, the solution to this equation is approximately x ≈ 9.0345.

4. (7x/9) - (11x - 7) = 8

Let's simplify this equation step by step:

(7x/9) - (11x - 7) = 8

Now, distribute the negative sign on the second term:

(7x/9) - 11x + 7 = 8

Next, isolate the terms with x on one side:

(7x/9) - 11x = 8 - 7

Now, find a common denominator (9) for the fractions:

(7x - 99x)/9 = 1

Combine like terms on the left side:

(-92x)/9 = 1

Now, multiply both sides by 9 to solve for x:

-92x = 9

Finally, divide by -92 to isolate x:

(-92x)/(-92) = 9/(-92)

x ≈ -0.0978 (rounded to four decimal places)

So, the solution to this equation is approximately x ≈ -0.0978.