Answer:
Total money, m(d) Cruz has = 30 d - 60
Explanation:
Cruz has d $10-bills.
Number of $10-bills Cruz having = d
He has 3 fewer $20-bills than he has $10-bills
Number of $20-bills Cruz having = d - 3
We need to find an expression to represent how much money Cruz has in dollars.
Total money, m(d) he has is given by
m(d) = 10 x d + 20 ( d- 3) = 10 d + 20 d - 60 = 30 d - 60
Total money, m(d) Cruz has = 30 d - 60