Graphing a logarithmlog

Question

y=(log₃X) -1 

 

When finding the table of values, I removed the brackets and did 3^y =x-1 but ended up with a different set then the one in my book. 

 

Also , if I were to convert y=3^x+1 , its supposed to convert to that logarithm but im confused about when to put the bracket. Why is -1 separated from the bracket?

Answer 1

y = log₃x - 1

x = 1, log₃1 = 0, log₃ x - 1 = -1, (1, -1)

x = 3, log₃3 = 1, log₃x - 1 = 0, (3, 0)

x = 9, log₃9 = 2, log₃x - 1 = 1, (9, 1)

x = 1/3,  log₃x = -1, log₃x - 1 = -2, (1/3, -2)