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Mathematics 7 Online
OpenStudy (pinknabastak):

4log2(x^2+2x+1)=16

OpenStudy (kc_kennylau):

\[\Large4\log_2(x^2+2x+1)=16\]

OpenStudy (kc_kennylau):

Factorize \(\Large x^2+2x+1\) first :) (Hint: it's a perfect square)

OpenStudy (solomonzelman):

\[Log_ab=c~~~~~~~~~~~a^c=b\]I was thinking of this.

OpenStudy (pinknabastak):

(x + 1 - √2)(x + 1 + √2)

OpenStudy (solomonzelman):

\[ALSO:~~~~alog(b)=Log(b^a)\]

OpenStudy (solomonzelman):

there is an easier way to do this.

OpenStudy (kc_kennylau):

@pinknabastak what you answered is \(x^2+2x-1\) not \(x^2+2x+1\)

OpenStudy (kc_kennylau):

@pinknabastak and I said it's a perfect square :)

OpenStudy (solomonzelman):

\[4Log_2(x^2+2x+1)=16\]divide both side by 4\[Log_2(x^2+2x+1)=4\]

OpenStudy (solomonzelman):

\[Log_ab=c~~~~~~~~~a^c=b\]

OpenStudy (pinknabastak):

ok @SolomonZelman soo what would be next?

OpenStudy (kc_kennylau):

@SolomonZelman you don't call that an "easier" way. you call that a harder way

OpenStudy (solomonzelman):

\[x^2+2x+1=2^4\]

OpenStudy (pinknabastak):

2^4=(x^2+2x+1)

OpenStudy (pinknabastak):

oh yea haha

OpenStudy (solomonzelman):

\[x^2+2x+1=2^4\]

OpenStudy (kc_kennylau):

@pinknabastak \[4\log_2(x^2+2x+1)=16\\4\log_2(x+1)^2=16\\8\log_2(x+1)=16\\\log_2(x+1)=2\\x+1=2^2\\x=3\]

OpenStudy (pinknabastak):

whats the next step in your way @SolomonZelman ? because thats the way my teacher has explained it before but still didnt exactly click but @kc_kennylau i see how your way is fast and it answers it as 3 but i would like to see all ways

OpenStudy (solomonzelman):

recalling. \[Log_2(x^2+2x+1)=4\]

OpenStudy (pinknabastak):

yes so how does that get to x=3?

OpenStudy (solomonzelman):

\[Log_2(x^2+2x+1)=4Log_22\]\[Log_2(x^2+2x+1)=Log_2(2^4)\]\[Log_2(x^2+2x+1)=Log_216\]\[x^2+2x+1=16\]

OpenStudy (solomonzelman):

and from then you can do it....

OpenStudy (solomonzelman):

But either way, I like how @kc_kennylau does it

OpenStudy (kc_kennylau):

I like your way too lolz :)

OpenStudy (solomonzelman):

The question of this type is just asking "Do you know the identities and how to use them?"

OpenStudy (pinknabastak):

ok thanks...:)

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