Question 864887
I'll do the first one to get you started



{{{y = 3.5(2.7)^x}}}



{{{y/3.5 = (2.7)^x}}} Divide both sides by 3.5.



{{{log((y/3.5)) = log(((2.7)^x))}}} Take the log of both sides (log can be any base, but I'm using base 10)



{{{log((y/3.5)) = x*log((2.7))}}} Pull down the exponent.



{{{log((y/3.5))/log((2.7)) = x}}} Divide both sides by {{{log((2.7))}}} to isolate x. Note: for some reason, there's this weird gap, so ignore it and pretend it's not there.



{{{x = log((y/3.5))/log((2.7))}}} 


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So we go from {{{y = 3.5(2.7)^x}}} to {{{x = log((y/3.5))/log((2.7))}}} after solving for x.