№ 86
а) 4 = 22; 8 = 23; 64 = 26; 16 = 24; 256 = 28; –8 = –23; –32 = –25; –64 = –26;б) 5 = 51; 25 = 52; 125 = 53; –25 = –52; –125 = –53.
вправи поруч