<PRE><B>Question 35290</B>
let x denote the number of nickels present in the vending machine
the number of dimes is 5 more than twice the number of nickels
therefore the number of dimes present in the vending machine is 2x + 5 

the total amount in the vending machine is $4.50 which is 450 cents

a dime is 10 cents and nickel is 5 cents

the amount from the dimes is (2x + 5)*10
the amount from nickels is x*5

(2x+5)*10 + 5*x = 450
25x + 50 = 450
25x = 400
x = 16
the number of nickels is 16
the number of dimes is 2*16 + 5 = 37</PRE>