Since all of the numbers share a common number that divides them, a simplified 4:22:30 ratio would be 2:11:15, as it would not be able to divide them further with the same number and still get whole numbers, or 1: 5.5: 7.5, if you wish to split them further to 1.
1- The interest rate is 7.5/year so 7.5/.75 year(9 months) at 500$ which would produce a profit of 28.13$ so a total of 528.13
2-7.5/year for 1.5 years(18 months) at 500$ so total interest is 56.25$ so the total is 566.25$
Answer:
The question is incorrect. if you are going to solve an equation for x you need to set it equal to something.