Question

My answer is A

What is the solution to the equation 9 -3x ≈ 7 ? (1 points)
Answer

x = 0.376

x = 0.295

x = -0.295

x = -0.376

Answer 1

so is this question

\[9^{-3x} = 7\]

Answer 2

yes sir

Answer 3

ok... so the log law you keep needing is

\[logx^a = a \times \log x\]

so using this and taking the log of both sides

\[\log(9^{-3x}) = \log(7)\]

using the above log law

\[-3x \times \log(9) = \log(7)\]

divide both sides of the equation by log(9)

\[-3x = \frac{\log(7)}{\log(9)}\]

now divide both sides of the equation by -3

\[x = \frac{-1}{3} \times \frac{\log(7)}{\log(9)}\]

if you put that into a calculator you should get one of your answer choices.

Answer 4

are you serious? that's really all you have to do?

Answer 5

to make it simple input

\[-1 \div 3 \times \log(7) \div \log(9)\]

Answer 6

I'm going to look at your work so i stop asking questions about this

Answer 7

yep... thats the log law you seem to have been using in the last few questions.

Answer 8

how did you know to put the -3x on the outside of the equation?

Answer 9

Also, the answer is C :)

Answer 10

because its the power.....there are a few log laws you need to know..

these notes are quite good... if you scroll down you'll see the log laws

http://tutorial.math.lamar.edu/Classes/CalcI/LogFcns.aspx

Answer 11

thank you for the material

Answer 12

the answer is C

Answer 13

youre a life saver! thank you so very much, really

Answer 14

glad to help... logs are a pain