x/4 < 5
__________
You can see it as multiplying on each side by four
(x/4)*4 < 5*4
x * (4* 1/4 ) < 5*4
x< 5*4
x< 20
_______________________
2x > 12
You can see it as dividing on each side by two
(2x) /2 > 12/ 2
x (2* 1/2) > 12/2
x > 6
you solve it as a normal equation it should not only maintain the relation >, <, ≤ or ≥ .