Question

2^x−4 +10 = 22

Answer 1

Please help!! this is urgent

Answer 2

Did you input the equation correctly?

Answer 3

\[2^{x-4}+10=22\] like that?

Answer 4

yes i did

Answer 5

Yeah @satellite73

Answer 6

subtract \(10\) from both sides to get
\[2^{x-4}=12\]as a first step

Answer 7

then use the change of base formula to solve for \(x-4\) via
\[x-4=\frac{\log(12)}{\log(2)}\]

Answer 8

and finally \[x=\frac{\log(12)}{\log(2)}+4\] and a calculator will give you a decimal approximation

Answer 9

But why do you do \[\log{2} \]

Answer 10

in the denominator?

Answer 11

Yes

Answer 12

you could always write
\[x-4=\log_2(12)\] if you like, but unless you happen to know what \(\log_2(12)\) is, which i doubt, you need the change of base formula

Answer 13

so it would be 14.3?

Answer 14

that is you could write as your answer
\[x=\log_2(12)+4\] but that doesn't really give you an answer

Answer 15

that is not what i get

http://www.wolframalpha.com/input/?i=log%2812%29%2Flog%282%29+%2B4

Answer 16

yeah that wasnt a choice in my answers but thats what my calculator gave me. illl try again

Answer 17

thank you so much! @satellite73