juliika2001

а) 4/5 = 3 :4Х                                б) 8/9 = 1/2Х

16Х = 15                                          16Х = 9

 Х = 15/16                                         Х = 9/16

в) 27/40 = 18Х/25

720Х = 675

   Х = 675/720

Х = 135 /144