You have the following stament:
The product of 8 and a number increased by 17
In order to write the previous statment in an algebraic way, you take into account that "the product of 8 and a number" means the multiplication of 8 and a variable, which is "increased" by 17. That is, number 8 is multiplying the sum of a variable and 17.
Thus, you have:
The product of 8 and a number increased by 17:
8(x + 17)