Logarithm, SMB-022 Solve `4^(x-1)=84` for `x`, giving your answer correct to 1 decimal place. (2 marks) --- 5 WORK AREA LINES (style=lined) --- Show Answers Only `4.2` Show Worked Solution `4^(x-1)` `=84` `log_10 4^(x-1)` `=log_10 84` `(x-1)log_10 4` `=log_10 84` `x-1` `=(log_10 84)/(log_10 4)` `x` `=(log_10 84)/(log_10 4)+1` `=4.196…` `=4.2\ text{(to 1 d.p.)}`