When air is pumped into an automobile tire, the pressure is inversely proportional to the volume. If the pressure is 30 pounds when the volume is 235 cubic inches, what is the
pressure, in pounds, when the volume is 150 cubic inches?
HELP MEEE PLSSS

Let us denote Maggie's years with M and her brother's years with Y.
We know that Maggie's brother is 5 years younger than three times her age.So, we can write:
Y=3*M-5 (1)
We also know that the sum of their ages is 51, so we can write:
Y+M=51 (2)
We can put the first equation (1) in the second (2) and we will obtain:
3M-5+M=51
4M-5=51
4M=51+5
4M=56
M=56/4
M=14
Maggie is 14 years old.
And her brother is : Y=51-14=34 years old.