Question

http://gyazo.com/56fd46cfc76fff81f550aa8807e65bba

Are these right?

79. c
80. b
81. ac
82. ae
83. ad
84. ab

Answer 1

yep

Answer 2

@iGreen Can you help me?

Answer 3

@iGreen we may need you

Answer 4

@AkashdeepDeb Can you look at these?

Answer 5

What's funny is, all are incorrect. But no worries. Let me clear some concepts here for you.

What is log?

It is a way to represent exponents. That's it.

When we say, \(y = \log x \) we actually mean, \(x = e^y\).

\[79. ~~10^{\log_{10} x}\]
Set this equal to \(y\).
Hence, \(y = 10^{\log_{10} x}\).
This is in exponent form now. Write this in logarithmic form. Remember \(y = \log x~\)? :D\[\log_{10} x = \log_{10} y ~~\therefore ~y=x\]Thus, \(y = 10^{\log_{10} x} = x\)

The same concept has been used till Q81. Redo them.

\[82. ~~\log_9 9^x\]
Not sure how you got this wrong as I told you the concept already.
\(\log_{a} b^n = n \log_{a} b\)

Use this in all the questions till Q84.

Understood? :)