[(b-3a)²]^(n+1)×【(3a-b)^(2n+1)】³
=[(3a-b)²]^(n+1)×【(3a-b)^(2n+1)】³
=(3a-b)^(2n+2)×(3a-b)^(6n+3)
=(3a-b)^[(2n+2)+(6n+3)]
=(3a-b)^(8n+5)
[(b-3a)²]^(n+1)×【(3a-b)^(2n+1)】³
=[(3a-b)²]^(n+1)×【(3a-b)^(2n+1)】³
=(3a-b)^(2n+2)×(3a-b)^(6n+3)
=(3a-b)^[(2n+2)+(6n+3)]
=(3a-b)^(8n+5)