Final answer:
The expression to show how many pages Bobby will read in n nights is 35n (option C).
Step-by-step explanation:
The expression to show how many pages Bobby will read in n nights is 35n (option C).
Since Bobby promised to read 35 pages each night, multiplying the number of nights (n) by 35 will give us the total number of pages he will read in n nights.
For example, if Bobby reads for 3 nights, the expression 35n becomes 35 x 3 = 105. So, Bobby will read 105 pages in 3 nights.