Question

1)9-2(-4х+7)=72)9+10(3х-10)=23) 7+9(4х+5)=-2​

Answer 1

1) 9 - 2 · (-4х + 7) = 7

2 · (-4х +  7) = 9 - 7

2 · (-4х + 7) = 2

-4х + 7 = 2 : 2

-4х + 7 = 1

-4х = 1 - 7

-4х = -6

х = -6 : (-4)

х = 1,5

Проверка: 9 - 2 · (-4 · 1,5 + 7) = 7

                   9 - 2 · (-6 + 7) = 7

                   9 - 2 · 1 = 7

                   7 = 7

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

2) 9 + 10 · (3х - 10) = 2

10 · (3х - 10) = 2 - 9

10 · (3х - 10) = -7

3х - 10 = -7 : 10

3х - 10 = -0,7

3х = 10 - 0,7

3х = 9,3

х = 9,3 : 3

х = 3,1

Проверка: 9 + 10 · (3 · 3,1 - 10) = 2

                   9 + 10 · (-0,7) = 2

                   9 + (-7) = 2

                   2 = 2

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

3) 7 + 9 · (4х + 5) = -2

9 · (4х + 5) = -2 - 7

9 · (4х + 5) = -9

4х + 5 = -9 : 9

4х + 5 = -1

4х = -1 - 5

4х = -6

х = -6 : 4

х = -1,5

Проверка: 7 + 9 · (4 · (-1,5) + 5) = -2

                   7 + 9 · (-1) = -2

                   7 - 9 = -2

                   -2 = -2

Answer 2

Let's solve these equations step by step:

1. 9 - 2(-4x + 7) = 7

First, distribute the -2 on the left side of the equation:

9 + 8x - 14 = 7

Now, combine like terms:

8x - 5 = 7

Add 5 to both sides of the equation:

8x = 12

Divide both sides by 8 to isolate x:

x = 12 / 8

x = 3/2

So, the solution to the first equation is x = 3/2.

2. 9 + 10(3x - 10) = 23

First, distribute the 10 on the left side of the equation:

9 + 30x - 100 = 23

Now, combine like terms:

30x - 91 = 23

Add 91 to both sides of the equation:

30x = 23 + 91

30x = 114

Divide both sides by 30 to isolate x:

x = 114 / 30

x = 19/5

So, the solution to the second equation is x = 19/5.

3. 7 + 9(4x + 5) = -2

First, distribute the 9 on the left side of the equation:

7 + 36x + 45 = -2

Now, combine like terms:

36x + 52 = -2

Subtract 52 from both sides of the equation:

36x = -2 - 52

36x = -54

Divide both sides by 36 to isolate x:

x = -54 / 36

x = -3/2

So, the solution to the third equation is x = -3/2.