how can you tell if an answer will be positive or negative for negative eponents
you cant. Lets take for example an equation of the form a0+a1*xt1+a2*xt2+a3*xt3..........an*xtn=0,
where t1 2 3<..... n<0
Now multiply by x-t1 and get: a0*x-t1+a1+a2*xt2-t1+a3*xt3-t1+a4*xt4-t1+a5*xt5-t1..........an*xtn-t1=0
the equation is exactly the same, no solution was added (you can check it)
So it doesnt tell anything about the answer.