Ask your own question, for FREE!
Mathematics 19 Online
OpenStudy (anonymous):

Hi, how do we prove that 3^(2m)*m+3m, is divisible by 4 ?

ganeshie8 (ganeshie8):

you wanto use congruences / binomial ?

ganeshie8 (ganeshie8):

\(3^{2m}*m + 3m \equiv (-1)^{2m}*m - m \equiv 0 \mod 4\)

OpenStudy (anonymous):

@ganeshie8 Could you explain ?

OpenStudy (anonymous):

Got it

ganeshie8 (ganeshie8):

good :) just need to see that \(3 \equiv-1 \mod 4\)

OpenStudy (anonymous):

but how does \((−1)^{2m}∗m−m = 0 mod 4\) ?

ganeshie8 (ganeshie8):

whats the value of \((-1)^{2m}\) after simplifying ?

OpenStudy (anonymous):

OOOOh

ganeshie8 (ganeshie8):

:)

OpenStudy (anonymous):

Exactly

OpenStudy (anonymous):

What about induction ?

ganeshie8 (ganeshie8):

definitely worth trying ! induction proof looke even more beautiful

OpenStudy (anonymous):

Yes let's get started.

OpenStudy (anonymous):

with \(0\) it's ok.

ganeshie8 (ganeshie8):

yes go straight to induction hypothesis

OpenStudy (anonymous):

\(m(3^{2m}+3)=0mod4\) is true. :)

OpenStudy (anonymous):

how about, \(m+1(3^{2m}*3+3)\)

OpenStudy (anonymous):

sorry \((m+1)\)

ganeshie8 (ganeshie8):

assume : \(k(3^{2k}+3) = 4n \) and prove : \((k+1)(3^{2(k+1)}+3) = 4t\)

OpenStudy (anonymous):

Yes

OpenStudy (anonymous):

@ganeshie8 from where can i find the 4 ?

ganeshie8 (ganeshie8):

its getting nasty lol... @Abhishek619 wana try :)

OpenStudy (anonymous):

It's difficult-

OpenStudy (anonymous):

@ganeshie8 \(-2m=0 mod4\) ?

OpenStudy (anonymous):

induction theorem

OpenStudy (anonymous):

?

OpenStudy (anonymous):

|dw:1397907875206:dw| It is divisible by 4.

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!