3f+3<6
(First get all the constants on one side and the variables on the other side.)
3f+3<6
-3 -3
----------
3f < 3
(Then divide by the number with the variable to isolate it.)
3f < 3
--- --
3 3
f < 1
It would be the same for this one also:
7f-20>50
+20 +20
________
7f > 70
-- ---
7 7
f > 10
