SOLUTION: Write a linear system that models the situation and solve. You have a total of 5 coins. Some are nickels and some are dimes. The total value is 40 cents. How many nickels and di

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Question 701307: Write a linear system that models the situation and solve.
You have a total of 5 coins. Some are nickels and some are dimes. The total value is 40 cents. How many nickels and dimes do you have?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
"You have a total of 5 coins" means x+y = 5 where x = # of nickels and y = # of dimes

"The total value is 40 cents" means 0.05x + 0.10y = 0.40 and you can multiply everything by 100 to get 5x + 10y = 40

So your system of equations is

x+y = 5
5x+10y = 40

Isolate y in the first equation to get: y = 5-x

Then plug this into the second equation to get

5x + 10y = 40

5x + 10(5-x) = 40

I'll let you solve for x. Once you have the solution for x, use it to find the solution for y.