Answer:
19 dimes and 9 nickels
Step-by-step explanation:
Model the situation using two equations, then solve the system.
let n be number of nickels and d be number of dimes.
n + d = 28 <= This equation is about the number of coins.
0.05n + 0.10d = 2.35 <=This equation is about the worth in dollars.
Rearrange n + d = 28.
n = 28 - d
Now we can substitute this equation into the other one.
Sub n =28-d at the "d" variable for the equation 0.05n + 0.10d = 2.35
0.05n + 0.10d = 2.35
Now there is only one variable.
0.05(28 - d) + 0.10d = 2.35 <=distribute this
0.05(28 - d) + 0.10d = 2.35
1.4 - 0.05d + 0.10d = 2.35 <=combine like terms
1.4 + 0.05d = 2.35 <= begin to isolate d
0.05d = 2.35 - 1.4
0.05d = 0.95
d = 0.95/0.05
d = 19
Now that we know d=19, we can substitute it into any equation.
Choose the equation n + d = 28 because the numbers are easier.
n + d = 28
n + 19 = 28 <=isolate n
n = 28 - 19
n = 9
Since n=9 and d=19, Kay has 9 nickels and 19 dimes.
