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Now that you are getting the idea, what can we do to solve this one?

7 = 10^( t )

Well, who can undo a  10^( t ) ?    log to the base 10

 !

 7 = 10^( t ) ... log( 7 ) = log( 10^( t ) ) ... log( 7 ) = t ... t = approximately .8451


TRY IT:

(I'm throwing a trick in, so be careful to clear the path!)

Solve5 = 2 * 10^( t )

And, no, you cannot multiply the 2 and the 10!


OK, now here's a tricky one!

Solve5 = 3^( t )

Think!  You know how this works now...

What can undo a  3^( t ) ?     log to the base 3 !

BUT, we don't have a

log to the base 3

button on our calculator!  Bummer.

WAIT!  The natural log can come to the rescue!

HOW?!