3x+5)/5+(9x-5)/4=6+ (3x+1)/2
((3х+5)*4))/20+((9х-5)*5)/20=(6*20)/20+((3х+1)*10))/20
(12х+20++45х-25)20=(120+30х+10)/20
(57х-5)/20=(130+30х)/20
(57х-30х)/20=(5+135)/20
27х/20=135/20
х=135:27
х=5
Проверка:
(3*5+5)/5+(9*5-5)/4=6+(3*5+1)/2
20:5+40/4=6+16:2
4+10=6+8
14=14