8.(88/88)^8/8 =(8^8/8^8)^8/8 =(8/8)^8 =88/9 8 lg(a8b8/8)/81 =lga^8+lgb^8/8-lg81 =8lga+8/8*lgb-8 8.不明白 8.没看懂 8.log8 ^8/88=log8 8(-8)=-8 8 8/8log8 88+log8 9/8 =log8 8 +log