x+3/20=5/12+2/9 .......

х=23/36-3/20
х=22/45
ответ: х=22/45

x + 320 = 512 + 29 
512 + 29 = 1536 + 836 = 2336
x + 320 = 2336
x = 2336 - 320 = 460720 - 108720 = 352720 = 176360= 88180 =4490 = 2245
x = 2245
2245 + 320 = 440900 + 135900 = 575900 =2336