1 = 2, 1] - 2, 1/2  , 1 + 2, 1/2, 1 )^2, 1 + 2 =, 1)^2, 1; 2, 1+ 2, 1+2, 1 -2, −1;2, (-1;2), [1; 2], (1) (2), 1 : 2, 1.2=....., 1 : 2 =?, −1.2, 1.2, (1)................................... (2)......................................, 1 : 2 = ..........., 1 * 2, 1-2