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 ??????

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!
Respond to this Question
Similar Questions

Math(Please check my work.)
(2x3)(x^2+5x3)=2x+10x^215x+9 *Is this correct.? 
algbrea
3x5(3x7)= 2(x+9) + 45 3x15x+35= 2x+18 +45 12x + 35 = 2x+63 12x 28 = 2x 12 28 =x 40 =x 3x5(3x7)= 2(x+9) + 45 3x15x+35= 2x+18 +45 12x + 35 = 2x+63 10x+35=63 10x=28 x=2.8 you are both wrong! 3x  15x + 35 = 2x + 18 + 45 … 
Algebra
Dylan has $2.30 in dimes and nickels. The dimes exceed nickels by 5. Find the# of each kind. let x= nickels= Let x+5= dimes= 2.3=(.05)x+(.10)x+5 2.3= .05x+.10x+5.1 2.3=.15x+5.1 2.8= .15x 18.666666666repeating=x what did i do wrong? 
algebra
15(3+x)=6x9 4515x=6x9 4515x+15x=6x+15x9 45=21x9 45=x9 45/9=5 x=5 is this right 
math
1. Ms.lynch has 21 coins in nickels and dimes. Their total value is $1.65. How many of each coin does she have? 
Math
f(x)=13x^2 15x14 g(x)=15x^3+14x^215x+12 find f(3) × f(10) + f(7) × g(9) 
math
Solve by elimination 5x+y=2 3x+y=1 This is what I got : 3(5x+y=2) 5(3x+y=1) 15x+3y=6 15x5y=5 2y=1 2 2 Y=1/2 15x+3(1/2)=6 15x+3/2 =6 15x/15= 9/2 /15 X=3/10 
Algebra
I need help trying to put the correct vocabulary words when solving this problem such as grouping, factor, prime factor, GCF, and perfect square, and please check and see if I am doing this correctly. 15x^2+31x+2 In my last problem … 
Algebra
I need help trying to put the correct vocabulary words when solving this problem such as grouping, factor, prime factor, GCF, and perfect square, and please check and see if I am doing this correctly. 15x^2+31x+2 In my last problem … 
Math?
Which expression is equivalent? −5(−3x − 6) A) 15x + 30 B) 15x − 30 C) −15x + 30 D) −15x − 30