2 4/7/(0,5х-23/35)=7,5
18/7=7,5*(0,5х-23/35)
18/7=75/10*5/10х-75/10*23/35
18/7=15/2*1/2х-3/2*23/7
18/7=15/4х-39/14
15/4х=18/7+39/14
15/4х=36/14+39/14
15/4х=75/14
х=75/14:15/4
х=75/14*4/15=2
(1/4+3.4x)/0,45=25/36
1/4+3,4х=25/36*45/100
1/4+3,4х=1/4*5/4
1/4+3,4х=5/16
0,25+3,4х=0,3125
3,4х=03125-0,25
3,4х=0,0625
х=0,0625:3,4
х=625/1000:34/10
х=625/1000*10/34
х=25/4*1/34
х=25/136