Algebra help! / finding x and simplifying?

(-3x + 4)/2 = 9
(-3x + 4)/2 = 18/2
-3x + 4 = 18
-3x + 4 - 4 = 18 - 4
-3x = 14
-3x/(-3) = 14/(-3)
x = -14/3


====
7x + 4 = 3x - 8
7x + 4 - 3x - 4 = 3x - 8 - 3x - 4
4x = -12
4x/4 = -12/4
x = -3


====
4 / [y/(x - 1)]
= 4 × [(x - 1)/y]
= 4(x - 1)/y

If there are three questions it is best to label them as 1 , 2 and 3
1
4 - 3x = 18
- 14 = 3x
x = - 14/3

2.
4x = - 12
x = - 3

3.
Will assume that what is actually meant is :-

4
--------------
y / (x - 1)

4 (x - 1)
------------
y

Whatever is meant , you MUST use brackets