Hi there!
[tex]\large\boxed{\text{9 quarters}}[/tex]
We can let x = dimes and y = quarters.
We know that one dime = $0.10 and a quarter = $0.25, so:
$3.05 = $0.10x + $0.25y
And:
17 = x + y
Solve the system of equations. We can rearrange the bottom equation to create an expression equal to y:
17 - x = y
Substitute this into the top equation for y:
3.05 = 0.10x + 0.25(17 - x)
Distribute and simplify:
3.05 = 0.10x + 4.25 - 0.25x
3.05 = 4.25 - 0.15x
Solve for x:
-1.2 = -0.15x
x = 8
Find y using the above expression:
17 - 8 = y
y = 9
