algebra
posted by mema .
Joe has a collection of nickles and dimes that is worth $7.65.If the number of dimes was doubled and the number of nickles was increased by 35, the value of the coins would be $14.30. How many nickles and dimes does he have?

It's spelled nickels.
Let x = number of nickels (originally)
let y = number of dimes (originally)
5x + 10y = 765
5*(x + 35) + 10*(2y) = 1430
5x + 20y = 1430  175 = 1255
The x terms are easily eliminated
10 y = 490
y = 49
5x = 765  490 = 275
x = 55