Let f(t)=2t²+3t-4

f(t+1)=f(t)+4t+5 TRUE or FALSE

answer is true, but i don't know how to get it, please help :(

re-arrange your answer to fit their answer.
I hope you had
f(t+1) = 2t² + 4t + 2 + 3t + 3 - 4 after you expanded
which is

f(t+1) = (2t² + 3t - 4) + 4t + 5
= f(t) + 4t + 5