Question

решите уравнения:
№1
0,8(х -2 ) - 0,7 ( х -1 ) = 2,7
№ 2
х+ 3 / 7= 2х -1 / 5
№ 3
0,3(х -2)= 0,6 + 0,2( х + 4)
№4
х + 4 / 6= 3х - 2/ 7

Answer 1

0.8(х-2)-0.7(х-1)=2.7
0.8х-1.6-0.7х+0.7=2.7
0.1х-0.9=2.7
0.1х=2.7+0.9
0.1х=3.6
х=3.6÷0.1
х=36
==========
(х+3)/7=(2х-1)/5
5(х+3)=7(2х-1)
5х+15=14х-7
14х-5х=15+7
9х=22
х=22÷9
х=22/9=2 4/9
===========
(0.3(х-2)=0.6+0.2(х+4)
0.3х-0.6=0.6+0.2х+0.8
0.3х-0.6=1.4+0.2х
0.3х-0.2х=1.4+0.6
0.1х=2
х=2÷0.1
х=20
==========
(х+4)/6=(3х-2)/7
7(х+4)=6(3х-2)
7х+28=18х-12
18х-7х=28+12
11х=40
х=40÷11
х=40/11=3 7/11