Answer:
F(n) = 8.5*n yards, where n is the number of windows
Step-by-step explanation:
Suppose the house of Stephen's aunt has n windows.
Since he needs 8.5 yards of fabric for each window, then he needs 8.5 times n yards of fabric for the n windows.
Call F(n) the yards of fabric he needs for the n windows, then
F(n) = 8.5*n
For example, if auntie's house had 4 windows, then
F(4) = 8.5*4 = 34 yards.
If auntie's house had 6 windows
F(6) = 51 yards.