can someone please help me with my algebra i got this as a answer and i don't know if its right.

N(t)= -3t^3 + 23t^2 + 8t
a. Rewrite the formula by factoring the right-hand side completely.
N(t)= -3t^3 + 23t^2 + 8t
N(t)= (-t)(3t^2 - 23t - 8)
N(t)= (-t)(3t+1)(t-8)
b. Use the factored version of the formula to find N(3).
N(t)= (-t)(3t+1)(t-8)
N(3)= (-3)(3(3)+1)(3-8)
N(3)= (-3)(9+1)(-5)
N(3)= (-3)(10)(-5)
N(3)= (15)(10)
N(3)= 150
C .the workers are most efficient in about 5 and a half hours because they make almost 250 components
d. The maximum number of components assembled per hour during a 8 hour shift is 1115 components.

a and b are correct, but I have no idea what you are talking about for c an d.