Question 100404: how do you solve ed has 30coins in nickles and in dimes in all he has 2.10 how many of each coins dose he have Answer by ptaylor(2198) (Show Source):
You can put this solution on YOUR website! Let x=number of nickels
Then 30-x=number of dimes
(1) value of the nickels=0.05x
(2) Value of the dimes=0.10(30-x)
Now we are told that (1) +(2)=2.10. So our equation to solve is:
0.05x+0.10(30-x)=2.10 get rid of parens
0.05x+3-0.10x=2.10 subtract 3 from both sides
0.05x+3-3-0.10x=2.10-3 collect like terms
-0.05x=-0.90 divide both sides by -0.05
x=18---------------------------number of nickels
30-x=30-16=12----------------- number of dimes
CK
0.05*18+0.10*12=2.10
0.9+1.2=2.10
2.10=2.10
