Let's make a system of equations to solve for this:
n + q = 84
0.05n + 0.25q = 12.80
where n = nickels and q = quarters.
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Solve for n in the first equation by subtracting q from both sides.
n = 84 - q
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Plug n into the second equation.
0.05(84 - q) + 0.25q = 12.80
Distribute 0.05 inside the parentheses.
4.2 - 0.05q + 0.25q = 12.80
Combine like terms.
4.2 + 0.2q = 12.80
Subtract 4.2 from both sides.
0.2q = 8.6
Divide both sides by 0.2.
q = 43
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Plug 43 for q in the first equation.
n + (43) = 84
Subtract 43 from both sides.
n = 41
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There are 41 nickels and 43 quarters in the piggy bank. ✅
Answer:
a = 195 ; c = 615
Step-by-step explanation:
So, you want to start by forming your equations...
I will use 'c' for children and 'a' for adults for my variables
3a + 30 = c
(this is because of the info that 30 more tickets than 3 times the amount of children's were sold than adult)
then for equation 2:
3c + 5a = 2820
(this is because of the prices of the tickets and the total money raised)
Then, plug in the equation for c
Your equation should look like:
3(3a + 30) + 5a = 2820
You get:
(9a +90) + 5a = 2820
Then:
14a = 2730
So:
a = 195 adult tickets sold
Plug in a, to find c:
3 (195) + 30 = c
585 + 30 = c
c = 615 children tickets sold
