Question

Даю 50 баллов.Решите уравнение: 1) 7х = -30 + 2х; 5) 0,2х + 4,3 = 0,4х - 6,5; 2) 16 - 18х = -25x - 12; 6) 0,6х + 100 = 0,9x + 1; 3)
-17х + 20 = 7х - 28; 7) -9/14 х + 18 =-2/3 х + 17; 4) 20 - 2х = 27 + х; 8) -8/15 х -11 = 4/9 х + 11.

Answer 1

1)7х-2х=-305х=-30х=-62)-18х+25х=-16-127х=-28х=-43)-17х-7х=-20-28-24х=-48х=25)0,2х-0,4х=-4,3-6,5-0,2=-10,8х=546)0,6х-0,9х=-100+1-0,3х=-99х=3307)-9/14х+2/3х=-18+17-27/42х+28/42х=-11/42х=-1х=-428)-8/15х-4/9х=11+11-24/45х-20/45х=22-44/45х=22х=-22,5задание 21)3х+х=28 2)5х-8х=-12+304х=28 -3х=-18х=7 х=63)8х+5х=-33+72 4)6х+х=19-1013х=39 7х=9х=3 х=9/75)-0,2х-0,3х=-0,7-1,8-0,5х=-2,5х=5

Answer 2

1) 7х = -30 + 2х; 
7х - 2x = - 30 
5x = - 30 
x = - 6 
---------------
5) 0,2х + 4,3 = 0,4х - 6,5; 
0,4x - 0,2x = 4,3 + 6,5 
0,2x = 10,8
x = 54
-------------------------------
2) 16 - 18х = -25x - 12; 
25x - 18x = - 12 - 16 
7x = - 28 
x = - 4 
----------------------------------
6) 0,6х + 100 = 0,9x + 1; 
0,9x - 0,6x = 100 - 1 
0,3x = 99
x = 330 
-----------------------------------
3) -17х + 20 = 7х - 28; 
7x + 17x = 20 + 28 
24x = 48 
x = 2 
--------------------------------
7) -9/14 х + 18 =-2/3 х + 17; 
- 9/14x + 2/3x = 17 - 18 
- 27/42x + 28/42x = - 1 
1/42x = - 1 
x = - 42 
-----------------------------
4) 20 - 2х = 27 + х; 
x + 2x = 20 - 27 
3x = - 7 
x = - 7/3 
x = - 2 1/3 
-------------------------------
8) -8/15 х -11 = 4/9 х + 11.
- 8/15x - 4/9x = 11 + 11
- 24/45x - 20/45x = 22 
- 44/45x = 22 
x = 22 : ( - 44/45 )
x = - 45/2 
x = - 22 1/2