(43-z)умножить 17=289
(43 - z ) * 17 = 289 43 - z = 289 : 17 43 - z = 17 43 - 17 = z z = 26 проверка (43-26)*17=26*17=289 - верно
( 43 - z ) • 17 = 289 43 - z = 289 : 17 43 - z = 17 z = 43 - 17 z = 26