Question

4) A safe contains 120 coins, the value of which is $10. If the coins consist of nickels and dimes, how many of each kind are in it?
5) A sum of $14 is made of 92 coins, consisting of dimes and quarters.How many are there of each kind of coin?
6) A boy's coins, consisting of nickels and dimes, amount to 42.15. If the number of dimes exceeds 3 times the number of nickels by 4, find the number of each kind of coin?

Answer 1

120=x+y and 10=.05x+.10y
120-x=y then subsitute 10=.05x+.10(120-x) distruibte and solve you can do it feel free to go off of my math.
x(nickels) y(dimes)