حل تمارين في الجافا؟؟

السلام عليكم 

ارجووووكم ساعدوني ولاتبخلو علي بمعلوماتكم 

اتمنى تساعدوني في حل التمارين هذي وتشرحولي هيا لو سمحتو 

1- Write a program that displays the sales tax with two digits after the decimal point

2-This program lets the user enter the amount in decimal representing dollars and cents and output a report listing the monetary equivalent in single dollars, quarters, dimes, nickels, and pennies. Your program should report maximum number of dollars, then the maximum number of quarters, and so on, in this order 

3-This program lets the user enter the interest rate, number of years, and loan amount and computes monthly payment and total

payment

 لاتردوووني خائبة ولكم جزيل الشكر