分からない問題はここに書いてね434 [無断転載禁止]©2ch.net

AB=2(A-2)(B-2)

AB = 2(AB-2A-2B+4)

AB = 2AB-4A-4B+8

0 = AB-4A-4B+8

0 = A(B-4)-4B+8

4B-8 = A(B-4)

4(B-4)+8 = A(B-4)

4+8/(B-4) = A