Exponential expression 6x to the 9th y to the -4 over 15x to the 5th and y to the -1

Kevin and randy muise have a jar containing 78 coins, all of which are either quarters or nickels. the total value of the coins in the jar is $13.90. how many of each type of coin do they have?

Complex numbers multiply √-4 * √-25 and show all intermediate steps. alternative notation is sqrt(-4) * sqrt(-25).

Which expression is equal to (f+g)(x)?