Answer:
• (a)0.25q+0.1d=13.75, q=2d-5
,
• (b)d=25
,
• (c)q=45
Explanation:
Let the number of quarters in his collection = q
Let the number of dimes in his collection = d
• 1 quarter = $0.25
,
• 1 dime =$0.10
The total value of his collection = $13.75.

He has five fewer quarters than two times the number of dimes.

The system of equations that describes the situation is:

Next, we solve for q and d.
Substitute the second equation into the first.
![\begin{gathered} 0.25q+0.1d=13.75 \\ 0.25(2d-5)+0.1d=13.75 \\ \text{Open the bracket} \\ 0.5d-1.25+0.1d=13.75 \\ \text{Collect like terms} \\ 0.5d+0.1d=13.75+1.25 \\ 0.6d=15 \\ \text{Divide both sides by 0.6} \\ (0.6d)/(0.6)=(15)/(0.6) \\ d=25 \end{gathered}]()
Finally, solve for q.

Jackson has 25 dimes and 45 quarters in his collection.