Answer:
55 quarters, 30 dimes
Explanation:
x: quarters
y: dimes
x + y = 85
0.25x + 0.10y = 16.75
Multiply first equation by 0.10 and subtract the two equations.
0.10x + 0.10y = 8.50
-(0.25x + 0.10y = 16.75)
-0.15x = -8.25
x = 55
now plug this x-value into the first equation.
x + y = 85
55 + y = 85
y = 30