You Think You Know your Math? NEVA!!

This is to test how smart you are at math But u cant use your calculator =O Im Suck at math so if you think u can do better then me go ahead and try~

1 WHAT IS 2+-2
2 What is : 5f=27? f=?
3 5+-3= ?? T .T omg so hard D:
4 what is : 4n=88? n=?
5 2.5r=15 what is r?
6 LAST QUESTION =o u are gonna get this one wrong im sure =3 WHAT IS 2+2?