Question 12080
1. 9(t-1)=(t+4)-t 
9t-9=t+4-t
9t-9=4       (((add 9 to both sides)))
(9t-9)+9=(4)+9
9t=13      (((divide both sides by 9
{{{9t/9}}}={{{13/9}}}
t={{{13/9}}} or 1{{{4/9}}} 

 



2. 40-{{{8s/5}}}=-2s            (((( multiply both sides by 5
(40-{{{8s/5}}})(5)=(-2s)(5)
200-8s=-10s                (((((((add 8s to both sides
(200-8s)+8s=(-10s)+8s
200=-2s                       divide both sides by -2
{{{200/-2}}}={{{-2s/-2}}}
-100=s