2^c=60=5*2*2*3=2^b*2*2*2^a=2^(2+a+b)
∴ c=2+a+b3a²*a²+2a*a²*a²-4a²*a²我会加分=3a^4+2a^5-4a^4=2a^5-a^43a²*a²的a²是a的4次方4a²*a²的4a²是4a^43a²*a^4+2a*a²*a²-4a^5*a²3a²*a^4+2a*a²*a²-4a^5*a²=3a^6+2a^5-4a^7