A+b+c=28x+40=180
—>28x=140
—>x=140/28=5
c=9x-3
—>c=42
Answer: 2x^9 Hope this helps!
The value of the coin times the number of coins all added up equals the total value of the piggy bank
so
0.05n + 0.10d = 5.60
then they have given us "number of nickels is 8 less than 3 times the dimes"
this translates to
n = 3d - 8
we plug this into our first equation and we get
0.05(3d - 8) + 0.10d = 5.60
now we solve for d
first we can distribute the 0.05
0.15d - 0.40 + 0.10d = 5.60
then we can add the 0.15d and 0.10d together
and get
0.25d - 0.40 = 5.60
then we can add 0.40 to both sides
0.25d = 6.00
then divide both sides by 0.25
d = 6.00 / 0.25 = 24
so we have 24 dimes
then to find nickels, we plug in 24 for d into
n = 3d - 8
and get
n = 3(24) - 8
n = 72 - 8
n = 64
therefore we have
64 nickels
and
24 dimes
Option a: 
is the solution to the system of equations.
Explanation:
The equations are 
and 
Equating these two equations, we have,
Taking LCM and multiplying both sides by 5, we get,
Simplifying , we get,
Substituting the value of x in , we get,
Thus, the solution is 
Changing the solution from fraction to decimal, we get, 
Thus, the solution is
Hence, option a is the correct answer.
