Question

7^x=12

Answer 1

ln7^x = ln12
xln7 = ln12
x = ln12/ln7 = 1.94

Answer 2

now is when you need the calculator!

Answer 3

wait it's 1.27

Answer 4

NOT 1.94..

Answer 5

Oh boy! How do u use the cal?

Answer 6

windows calculator SUCKS!

Answer 7

you solve
\[b^x=A\] for x in one step only.
\[b^x=A \iff x=\frac{\log(A)}{\log(b)}\]

Answer 8

this is sometimes called "change of base formula" and if you remember i just showed you how to cheat on
\[\log_b(A)\] by computing
\[\log(A)\div \log(b)\]

Answer 9

this is exactly the same. you are trying to find
\[\log_7(12)\] but of course you do not have log base 7 on your calculator. so instead you take out calculator and type in
\[\log(A)\div \log(7)\] and out pops answer

Answer 10

dumb question, what is A?

Answer 11

ok the general form is
\[b^x=A\] and you want x. you have
\[7^x=12\] so what is A?

Answer 12

12?

Answer 13

yes. so you solve by typing in
\[\log(12)\div \log(7)\] in english, "the log of the total divided by the log of the base"

Answer 14

bahrom solved using
\[x=\ln(12) \div \ln(7)\] you can check you get the same answer it makes no difference which log you use

Answer 15

yes!! I am excited:)

Answer 16

Thank you so much!! God bless u:)