Question

781. 1) 3,4x - 4 = 4,8 – x;2.782. 1) x = 2/3x + 1;3783. 1) 7x - (3 + 2x) = x + 9;​

Answer 1

781. 1) 3,4х - 4 = 4,8 - х

3,4х + х = 4,8 + 4

4,4х = 8,8

x = 8,8 : 4,4

х = 2

Ответ: х = 2

782. 1) x = 2/3x + 1

x = 2x/3 + 3/3

x = 2x + 3/3

3x = 3 • 2x + 3/3

3x = 2x + 3

x = 3

Ответ: x =3

783. 1) 7х - (3 + 2х) = х + 9

7х - 3 - 2х = х + 9

7х - 2х - х = 3+9

4х = 12

х = 12:4

х = 3

Ответ: x = 3

Answer 2

It seems like you've provided three different equations. Let's solve each of them:

Equation 1 (781):

3.4x - 4 = 4.8 - x

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

3.4x + x = 4.8 + 4

Combine like terms:

4.4x = 8.8

Now, divide both sides by 4.4 to isolate x:

x = 8.8 / 4.4

x = 2

Equation 2 (782):

x = 2/3x + 1

Let's first get all the x terms on one side:

x - (2/3)x = 1

To combine the fractions, you can find a common denominator, which in this case is 3:

(3x/3) - (2x/3) = 1

Now, combine the fractions:

(3x - 2x) / 3 = 1

x / 3 = 1

Now, to isolate x, multiply both sides by 3:

x = 3

Equation 3 (783):

7x - (3 + 2x) = x + 9

First, distribute the negative sign on the left side:

7x - 3 - 2x = x + 9

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

7x - 2x - x = 9 + 3

Combine like terms:

4x - 3 = 12

Add 3 to both sides:

4x = 15

Now, divide both sides by 4 to isolate x:

x = 15 / 4

x = 3.75

So, the solutions to the equations are:

1. Equation 1: x = 2
2. Equation 2: x = 3
3. Equation 3: x = 3.75