An executive invests $23,000, some at 8% and the rest at 7% annual interest. if he receives an annual return of $1,800, how much is invested at each rate?

Sorry guys but as you have a small brain

Witch represents the inverse of the function f(x)=1/4x-12

Acollection of coins has value of 64 cents. there are two more nickels than dimes and three times as many pennies as dimes in this collection. how many of each kind of coin are in the collection?