-16-1.4х=-0.9х-16
-16+16=-0.9+1.4х
0.5х=0
х=0
Проверка:
-16-1.4х0=-0.9х0-16
-16-0=0-16
-16=-16
8(-х-2)=-5х-(6-9х)
-8х-16=-5х-6+9х
-8х+5х-9х=-6+16
-12х=10
х=-10/12
х=-5/6
Проверка:
8х(-(-5/6)-2)=-5х5/6-(6-9х(-5/6))
40/6-16=25/6-6-45/6
40/6-16=25/6-6-45/6
40/6-25/6+45/6=-6+16
60/6=10
10=10