30 points. simplify this with all steps

Simplify the following:
(5 i^3 t^4)/7 - 2
i^3 = i^2×i = (-1) i = -i:
(5×-i t^4)/7 - 2
Put each term in (5 (-i) t^4)/7 - 2 over the common denominator 7:
(5 (-i) t^4)/7 - 2 = (-5 i t^4)/7 - 14/7:
(-5 i t^4)/7 - 14/7
(-5 i t^4)/7 - 14/7 = (-5 i t^4 - 14)/7:
  (-5 i t^4 - 14)/7

That’s what i got when i looked up what the solutions were