What is a perpendicular lines

Which logarithmic equation is equivalent to the exponential equation below? e^a=55(you will receive 34 points)

Solve 2^x=32 and rewrite this equation in a logarithmic form

Tim's phone service charges $26.39 plus an additional $0.21 for each text message sent per month. if tim's phone bill was $31.64, which equation could be used to find how many text messages, x, tim sent last month?