-np - 90 < 30....for n
-np < 30 + 90
-np < 120
-n < 120/p
n < - 120/p
not sure if ur looking for m or h on the 2nd one..so I will do both
5m - 3h = 45....for m
5m = 45 + 3h
m = (45 + 3h)/5 = 3/5h + 9
5m - 3h = 45...for h
-3h = 45 - 5m
h = (45 - 5m)/-3 = 5/3m - 15
