KAlgebra/Credit payment

1.Write this Function in console mode.It calculates the monthly interest rate by given yearly interest rate.

monthlyInterestRate:= yearlyInterestRate-> x/1200

2.Write this Function in the console mode.It calculates the monthly payment you have to return to the bank

monthly_payment:=(sum, mir, months)->(sum*mir^months*(mir-1))/(mir^months-1))

3.Write this Function in the console mode.It calculate the whole sum you have to return to the bank

sum:=(monthlyPayment,months)->monthlyPayment*months