Which of the following equations is equivalent to b^y=x

Step-by-step explanation:
[tex]\text{De}\text{finition of logarithm}:\\\\\log_ab=c\iff a^c=b,\ \text{where}\ a>0\ \wedge\ a\neq1\ \wedge\ b>0\\\\\text{Therefore your answer is}\\\\\large\huge{\boxed{B.\ y=\log_bx}}\\\\\log_bx=y\iff b^y=x[/tex]