Question

Помогите решить уравнения:
1)1/3+1=-1/4(х+4/5)
2)2х+(5-7х)=15
3)5х+3=-3х+19
4)3х+4(5-3)=-7

Answer 1

2х+(5-7х)=15
2х-7х=15-5
-5х=10
х=10:(-5)
х=-2
2*(-2)+(5-7*(-2))=15
-4+(5+14)=15
-4+19=15
15=15
5х+3=3х+19
5х-3х=19-3
2х=16
х=16:2
х=8
5*8+3=3*8+19
43=43
3х+4(5-3)=-7
3х+4*2=-7
3х+8=-7
3х=-7-8
3х=-15
х=-15:3
х=-5
3*(-5)+4(5-3)=-7
-15+8=-7
-7=-7