Question

If log $2=.3010and\log 3=.4771$, the value of $x$ when $3^{x+3}=135$ is approximately:

• A. $5$
• B. $1.47$
• C. $1.67$
• D. $1.78$
• E. $1.63$

Answer 1

The correct option is B $1.47$

$3^x{.3}^3=135;\therefore 3^x=5;$
$\therefore xlog3=log5=log\left(10/2\right)=log10-log2.$
$\therefore x=(1-0.3010)/0.4771\sim 1.47$.