5t-10t^2÷5t

3 answers

if you wanted to simplify, we would get 5t--2t = 5t+2t = 7t
Taking into account the usual carelessness with parentheses, if you meant

(5t-10t^2)/5t, then you would have 1-2t

Otherwise, keeping track of the signs, you'd have 5t-2t = 3t
I'll go with Steve's answer

the other one mystifies me.