5 + 2х =0
2х=-5
х= -5/2
х=-2,5
проверим:
5 + 2*(-2,5) =0
5 + (-5) =0
0=0
2х+6=3+5х
2х -5х= 3-6
-3х=-3
х= (-3) /(-3)
х=1
проверим:
2*1 +6 = 3+5*1
8=8
5(1-х) +8х= -2-(2х+3)
5 - 5х +8х = -2 -2х -3
5 + 3х = - 5 - 2х
3х+2х=-5 - 5
5х= -10
х= -10/5
х=-2
проверим:
5 ( 1 - (-2)) + 8 *(-2) =-2-(2 *(-2) +3)
5 (1+2) + (-16) = -2 - (-4+3)
5*3 - 16 = -2 -(-1)
15 -16 = -2 +1
-1 = -1