Question

Pleaaw show graph f(x) = -x+6

Answer 1

This isn't an answer, rather a suggestion. I would use the website desmos to help me. But for future reference I can help you.

f(x) = - x+6 is similar to y=-x+6.

Simply plug in random numbers into the variable x (preferably ones that could fit on your paper like 0,1,2,3...)