Question

Help!! 2^x=.4 how to solve without a calc

Answer 1

well you square both sides which cancels out the x and you get X=2

Answer 2

ooops very sorry i wrote it wrong
2^x=.4

Answer 3

oh haha

Answer 4

okay! gimme a sec.

Answer 5

okay :p

Answer 6

since you cant make the base = you have to use log

Answer 7

but in class i learned only how to solve without calculator, and i will learn it in the next sections, may I know how to do that
thanks

Answer 8

take this problem
\[7^x=12\]
\[\ln 7^x=\ln 12\]
\[x \ln 7= \ln 12\]
\[x=\frac{ \ln 12 }{ \ln 7 }\]
\[\approx 1.277\]
this is straight out of my algebra book.

Answer 9

thank you very much