Trying to strengthen my math skills

I am trying to advance in my math skills and took some time to do a little algebra. I worked these problems and want to know if I got them right.

23 = p - 4

p - 4 -23

p - 27

-3x + 5 = 2

-3x = 2 - 5

-3x/-3x = -3/-3

x = 1

4 + d = 4 - 5 (d - 1) - 3

4 + d = 4 - 5d + 5 - 3

4 + d = -5d + 6

4 - 6 = -5d - d

-2 = -6d

-2/-6 = 1/3d

9/7 + 8/6x = -1/6x + 1

42 (3/4 + 2/6x = -1/6x + 1)

18 + 14x = -7x + 42

18-42 = -7x+ 42

-24 = -12x

-24 * 3/-21 * 3

x = 8/7

x + 2/8 + x-2/12 = 3

24 (x + 2/8 + x - 2/12 = 3) = 3 8 24/72

3x + 6 + 2x - 4 = 72

3x + 2x = 72 - 6 + 4

5x/5 70/5 = 14

x = 14

the perimeter of a triangle is 144. What are the consecutive even integers for each side?

x + x + 2 + x + 4 = 144

3x + 6 = 144

144 - 6 = 138

3x/3 138/3 = 46

46...48...50 are the consecutive even integers

5z - 12 >= 6z - 8 >= 4

5z - 6z >= 12 - 8 >= 4

-1z >= 4 >= 4

cannot be solved

5 (4 - 3x) < 7 (3 - 4x) + 12

20 - 15x < 21 - 28x + 12

20 - 12 - 12 < 28x - 15x

-13 < -13x

< 1

8x - 23/6 + 1/3 >= 5/2x

I couldn't figure this one out but I tried it.

2 * 8x - 23 + 4 >= 6 * 5

16x - 23 >= 4 >= 30

I think I got all of those right.