(3х+1)/5=(2х+4)/10
5(2х+4)=10(3х+1)
2х+4=2(3х+1)
2х+4=6х+2
6х-2х=4-2
4х=2
х=0,5
(5х-6)/4-(3х-6)/2=0
(5х-6)/4=(3х-6)/2
4(3х-6)=2(5х-6)
2(3х-6)=5х-6
6х-12=5х-6
6х-5х=12-6
х=6
(х+3)/5+(2х+4)/3=-5
3(х+3)+5(2х+4)=-5*15
3х+9+10х+20=-75
13х=-75-9-20
13х=-104
х=-8