So for the first one... Let's just use x for months and m for minutes.
(20m)+(.15m)
20 times the number of months plus .15 times the number of minutes
Same for the next one
(35x)+ (.10m)
35 times the number of months +.10 times the minutes.
Elaborate more on your question! Include details that we don't know.
The expanded algorithm is given as follows:
4 x 57 = (4 x 50) + (4 x 7) = 200 + 28 = 228
The standard algorithm is given as follows:
You solve for x and get x<-2 or x>= -1/2 and then graph