Starting inequality: 19 - 3x < 7

Subtract 19 from both sides, to get:
19 - 3x - 19 < 7 - 19
-3x < -12

Divide both sides by (-3),
which reverses the inequality:
-3x
-3
> -12
-3

x > 4

Solution Set in interval notation: (4, )
Solution set pictured on a number line

Update courtesy of Jen Womak, Topeka, Kansas