Question

PROBLEM SOLVING USING SYSTEMS OF EQUATIONS
There are 28 coins that are all nickles and dimes. The value is $2.05. How many nickles are there and how many dimes?

Answer 1

let x = no. of nickels
y = no. of dimes

x + y = 28
5(cents)x + 10(cents)y = 205 cents

multiply the first equation by -10

-10x -10y = -280
5x + 10y = 205

-5x = -75
x = 15

There are 15 nickels and 13 dimes.

Answer 2

you can also use
x+y=28
.05x+.10y=2.05

Answer 3

N + D = 28
5N + 10D = 205

-5(N + D = 28)
5N + 10D = 205

-5N - 5D = 140
5N + 10D = 205
--------------------------
5D = 65
D = 13
N = 15
There were 13 dimes and 15 nickels

Answer 4

thankyou so much!

Answer 5

no problem