Question
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=21-1.50
0.15x=19.5
------
0.15 = 19.5/ 0.15
x=130 ??????
21 - ( 0.05x + 0.10x)=1.50
21- 0.15x = 1.50
0.15x=21-1.50
0.15x=19.5
------
0.15 = 19.5/ 0.15
x=130 ??????
Answers
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 21-x
Now for the value of those coins:
5x + 10(21-x) = 165
5x + 210 - 10x = 165
-5x = -45
x = 9
then 21-x = 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!
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 21-x
Now for the value of those coins:
5x + 10(21-x) = 165
5x + 210 - 10x = 165
-5x = -45
x = 9
then 21-x = 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!