Answer:
70 25 centavo pieces
60 5 centavo pieces
Step-by-step explanation:
Let x = number of 25 centavo pieces
y = number of centavo pieces
The total number of pieces is 130
x+y = 130
The total amount is 20.50
.25x+.05y =20.50
Solve for y
x+y = 130
y = 130-x
Substitute into
.25x+.05y =20.50
.25x +.05(130-x) = 20.50
Distribute
.25x +6.5-.05x = 20.50
Combine like terms
.2x +6.5 = 20.50
Subtract 6.5 from each side
.2x +6.5-6.5 = 20.5-6.5
.2x =14
Divide each side by .2
.2x/.2 = 14/.2
x = 70
Now we can solve for y
y = 130-x
y = 130-70
y = 60
