Question 811778
dimes = x
quarters = y
24 coins are the number of dimes and number of quarters
x + y = 24
dimes are .10 and quarters are .25 and we want 4.50.
.10x + .25y = 4.50
now solve the first equation for y
x + y = 24
y = 24 - x
now use the substitution method to plug this into the other equation.
.10x + .25(24 - x) = 4.50
.10x + 6 - .25x = 4.50
-.15x = -1.50
x = 10
now plug this into the first equation
10 + y = 24
y = 14
We now know we have 10 dimes and 14 quarters.