17(3х-16)=238   8(133-5х)=864    

51х - 272 = 238
51х = 510
х = 10
1064 - 40х = 864
40х = 200
х = 5

1) 51х-272=238
51х=238+272
51х=510
х=510:51
х=10
2) 1064-40х=864
-40х=864-1064
-40х=-200
х=-200÷(-40)
х=5