(x+3)/7=(2x-1)/5 /-дробная черта

5×(х+3)=7×(2х-1) 5х+15=14х-7 5х-14х=-15-7 -9х=-22 х=22/9 х=2 4/9

(5(Х+3)-7(2х-1))/35=0(5х+15-14х+7)/35=0(-9х+22)/35=0-9х+22=0-9х=-22Х=22/9