Verified answer

232:х+21=50

232:х=50-21

232:х=29

х=232:29

 х=8

  (х-18)*17=408

х-18=408:17

х-18=24

х=24+18

х=42

232х = 50-21

232х= 29

х= 232 / 29

х = 8

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17х - 306 = 408

17х = 408+306

17х = 714 

х = 714 / 17

х = 42