Math
posted by verna .
Ms.lynch has 21 coins in nickles and dimes.Their total value is $1.65. How many of each coin does she have?
21  ( 0.05x + 0.10x)=1.50
21 0.15x = 1.50
0.15x=211.50
0.15x=19.5

0.15 = 19.5/ 0.15
x=130 ??????

Math 
Reiny
Your equation makes no sense to me at all
An equation only is useful and meaningful if the variable has been defined.
Let the number of nickels be x
then the number of dimes is 21x
Now for the value of those coins:
5x + 10(21x) = 165
5x + 210  10x = 165
5x = 45
x = 9
then 21x = 12
So we have 9 nickels and 12 dimes.
check:
do I have a total of 21 coins ? YES
value of my coins
= 5(9) + 10(12) = 165
All is good!
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