Jessica's bank contains 18 quarters & dimes, of which q are quarters. Find the total value of the coins in dollars.
To find the total value of the coins in dollars, we need to determine the value of each type of coin and then add them together.
Let's start by finding the value of quarters. Since each quarter is worth $0.25, we can multiply the number of quarters (q) by $0.25 to get the value of the quarters in dollars.
Value of quarters = q * $0.25
Next, let's find the value of dimes. Each dime is worth $0.10. We know that the total number of quarters and dimes is 18, so we can subtract the number of quarters (q) from 18 to find the number of dimes.
Number of dimes = 18 - q
Now, we can multiply the number of dimes by $0.10 to get the value of the dimes in dollars.
Value of dimes = (18 - q) * $0.10
Finally, we can add the value of the quarters and the value of the dimes together to find the total value of the coins in dollars.
Total value of coins = Value of quarters + Value of dimes
Total value of coins = q * $0.25 + (18 - q) * $0.10
Simplifying the equation, we get:
Total value of coins = $0.25q + $0.10(18 - q)
Total value of coins = $0.25q + $1.80 - $0.10q
Total value of coins = $0.15q + $1.80
So, the total value of the coins in dollars is $0.15q + $1.80.