2 questions

[Guest]

I forget howto do these two types of questions:

SOLVE AND CHECK.
-5^x+2=-1


and


4(6^g+2)=144

 

[Guest]

-5^x+2=-1

Start getting x on one side by itself.

-5^x + 2 = -1

<==> -5^x = -3

<==> 5^x = 3

Take log₅ of both sides. (Any base would work, but base 5 looks nicer.)

<==> log₅(5^x) = log₅(3)

log_b(a) means "the exponent that you put on b to get a". So log₅(5^x) means "the exponent that you put on 5 to get 5^x", which is of course x.

<==> x = log₅(3)

To check it, plug that back into the original equation and see if it's true.

If you meant 5^(x + 2), rather than 5^x + 2, then you just need to make some little modifications to this.