What is the expression for f(x) when we rewrite 36^x • 6^x-2 as 6^f(x)

This is a map of the mars exploration rover opportunity predicted landing site on mars. the scale is 1cm : 9.4km. what are the approximate measures of the actual length and width of the ellipse? i mostly need to know how to set it up : )

Solve for x and select the correct answer

Can someone me with this? i’m not sure what to put for my equations.