Please tell me how do you find the Long term liabilities

I know that you are supposed to remove the current liability from something in order to get the non current liabilty but it doesn't make sense to why you're substracting it. Please explain me why this weird thing is done when you give the answer

From the formation of FCI to the end of Year 10, the following transaction is the only transaction that has happened: FCI issues an installment note on August 1, Year 7 (with a required yield of 6%) in exchange for the land that it purchases from Mr. Mac. Mr. Macs real estate agent had listed the land on the market for $135,000. The note calls for three equal blended payments of $45,000 that are to be made at August 1, Year 8, Year 9, and Year 10. Note that FCIs fiscal year end is December 31. What is the amount of long-term liabilities that should be reported on December 31, Year 8 Statement of Financial Position?