Please help me answer this question step by step, the answer is 330.34. And what means the equation of value is 800 s angle 12 @ 8% + X s angle 12 @ 4% = 8000*(1.08)^12

Thank you!

A 12-year loan of 8000 is to be repaid with payments to the lender of 800 at the end of each year and deposits of X at the end of each year into a sinking fund. Interest on the loan is charged at an 8% annual effective rate. The sinking fund annual effective interest rate is 4%. Calculate X