Math question

t(t​^3​​+2t^​2​​−4t+5)

(7t^5+14t^4-28t^3+35t^2)/7t

$\frac{(7t^5+14t^4-28t^3+35t^2)}{7t}\\ =\frac{7t^5}{7t}+ \frac{14t^4 }{7t}+ \frac{-28t^3 }{7t}+ \frac{35t^2} {7t} \\ = t^4 + 2t^3-4t^2+5t$