Question

Angelina has a collection of Nickles and dimes worth 4.65 . If she has 70 nickles and dimes , how many of each does she have ?

Answer 1

23 dimes and 47 nickels   23+47=70

4.65=465cents

23 dimes=230 cents

47nickels=235cents

230+235=465cents

Answer 2

System of equations (yay) x=nickels y=dimes
1st  x+y=70
2nd  .5x+.10y=4.65
3rd  Move decimal (multiply everything by 100) :  5x=10y=465

x+y=70
-x         -x
y=70-x

(Substitute) 5x+10(70-x)= 465
(Distribute) 5x+700-10x=465
(Solve equation) -5x=-235 >>> x=47 >>> 
Answer- 47 dimes and 23 nickels

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