Final answer:
The expression for the sum of the ages of Nora, her father, and her brother, where y represents Nora's age, is 5y + 5.
Step-by-step explanation:
The student is asking for an expression that represents the sum of the ages of Nora, her father, and her brother given that her age is y, her father's age is three times hers, and her brother's age is 5 years more than hers. To find the sum of their ages, we can use the given information to set up the following equation:
Let Nora's age = y years.
Then, her father's age = 3y years (since it is thrice Nora's age).
Her brother's age = y + 5 years (since it is 5 years more than Nora's age).
Adding them together gives us:
Sum of their ages = Nora's age + Father's age + Brother's age
Sum of their ages = y + 3y + (y + 5)
Sum of their ages = 5y + 5
Thus, the expression for the sum of their ages in terms of y is 5y + 5.