It is a function because the input does not repeat itself.
Answer:
pages
Step-by-step explanation:
Variable:
x = number of pages he has to read on a weekday
x + 30 = The number of pages read on Saturday and Sunday




Meaning that Raoul has to read 59 pages on Wednesday
Let :
T = Theresa age
H = her brother
We know :
T = H - 14
T + H = 35
Substitute T
H -14 + H = 35
2H - 14 = 35
2H = 49
H = 49/2 = 24.5
Since we know H = 24.5 we then can substitute it to either equation.
T = H - 14
T = 24.5 - 14
T = 10.5
Theresa is 10.5 years old
Her brother is 24.5 years old
The answer to this is 7.5.