Ok the question is as follows:(adsbygoogle = window.adsbygoogle || []).push({});

Given gcd(a,b)=d, show that Phi(ab)= (d*phi(a)phi(b))/phi(d)

I know that if gcd(a,b)=1 then phi(ab)=Phi(a)phi(b) but im just stuck here. Any help would be greatly appreciated!

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# Homework Help: Euler's Phi function Number Theory

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