Answer:
a. $(675-18t)
b. $477
Explanation:
a. We are to write an expression that shows the total amount in both accounts.
Mathematically that would be; amount in the expense account + amount in the fund raising account
That would be ; 500-60t + 175 + 42t = 500+175-60t + 42t = 675 - 18t
The total amount in both accounts is $(675 - 18) after t weeks
B. after 11 weeks, what we do is to just substitute the value of 11 for t in the added equation above
Thus;
675 -18t = 675-11(18) = 675 - 198 = $477