Answer:
Dillion has 42 quarters and 15 dimes.
Step-by-step explanation:
Let the number of quarters=q
Let the number of dimes=d
Dillon has saved 57 coins in his piggy bank.
Therefore:
q+d=57
Now, 1 dime=$0.10 and 1 quarter=$0.25.
We multiply the value of each coin by the number of coins present.
Since Dillion has a total of $12
Therefore:
0.1d+0.25q=12
We solve the two equations simultaneously.
From equation 1, q=57-d
Substitute q=57-d into 0.1d+0.25q=12
0.1d+0.25(57-d)=12
0.1d+14.25-0.25d=12
0.1d-0.25d=12-14.25
-0.15d=-2.25
Divide both seides by -0.15
d=15
Recall: q=57-d
q=57-15=42
Therefore, Dillion has 42 quarters and 15 dimes.
Answer: 42 quarters and 15 dimes.
Step-by-step explanation:
If q is the number of quarters, and d the number of dimes, we have that:
q + d = 57
q*0.25 + d*0.10 = 12
the first step is isolating one of the variables in one of the equation, it is easier to do it in the first one, let's isolate q.
q = 57 - d
now, we can replace this in the second equation and solve it for d.
q*0.25 + d*0.10 = 12
(57 - d)*0.25 + d*0.10 = 12
57*0.25 +d*(0.10 - 0.25) = 12
57*0.25 - d*0.15 = 12
-d*0.15 = 12 - 57*0.25 = -2.25
d = (-2.25)/(-0.15) = 15
So the number of dimes is 15, this means that the number of quarters must be:
q = 57 - d = 57 - 15 = 42
