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Taylor has $3.00 in dimes and pennies. The number of pennies is 3 more than the number of dimes. Solve the equation 0.10d+0.01(d+3)=3 for d, the num d= dimes

User Campo
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1 Answer

3 votes

Answer:

d = 27

Explanation:

We need a stem of equations to find d, the number of dimes.

First equation:

We know that the sum of the number of dimes and pennies (p) equals 3:

0.10d + 0.01p = 3

Second equation:

We also know that the number of pennies is 3 more than the number of dimes:

p = d + 3

Plug in p = d + 3 for p in 0.10d + 0.01p = 3 to find d:

0.10d + 0.01(d + 3) = 3

0.10d + 0.01d + 0.03 = 3

0.11d + 0.03 = 3

0.11d = 2.97

d = 27

Thus, Taylor has 27 dimes.

Optional step:

We can check our work by finding the number of pennies. We can do this by plugging in 27 for d in p = d + 3:

p = 27 + 3

p = 30

Now we can plug in 2 for d and 30 for p in p = d + 3 and 0.01p + 0.10d = 3. If we get the same answer on both sides of the equaitons for both equations, our answer for the number of dimes is correct:

Checking solutions with p = d + 3:

30 = 27 + 3

30 = 30

Checking solutions with 0.01p + 0.10d = 3:

0.01(30) + 0.10(27) + 3

0.30 + 2.70 = 3

3 = 3

Thus, our answers are correct.

User Parakmiakos
by
8.2k points
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