Final answer:
Cruz has d $10 bills and he has 4 fewer $20 bills, represented algebraically as 10d + 20(d - 4). Simplifying the expression, we get 30d - 80 as the total amount of money Cruz has in dollars.
Step-by-step explanation:
Cruz has d $10 bills and 4 fewer $20-bills than he has $10-bills. To express how much money Cruz has in dollars, we need to create an algebraic expression that combines both the value of the $10 bills and the $20 bills.
Since he has d $10 bills, the expression starts with 10d (meaning 10 times d). Each $10 bill is worth $10, so if he has d of them, he has 10 times d dollars from the $10 bills.
Since he has 4 fewer $20 bills than the number of $10 bills, he has (d - 4) $20 bills. So, the expression for the $20 bills is 20(d - 4), meaning 20 times (d minus 4).
Combining both parts, we add 10d for the $10 bills to 20(d - 4) for the $20 bills, resulting in the expression 10d + 20(d - 4). This represents the total amount of money that Cruz has.
The simplified expression is obtained by distributing the 20 into the parentheses: 20d - 80. So, when we add 10d to the result, we get 10d + 20d - 80, which further simplifies to 30d - 80.