first, love the killua profile picture ! i love hunterxhunter i am currently on season 5, episode 44 or 45 aka 119 or 120 but anyways,
answer:
b = 2
Explanation:
because its roots are -4 and 2,
and a = 1 [The coefficient of
] we know that
using the distributive property we get,

by equating coefficients (common strategy for partial fractions and undetermined coefficient method of solving ODE), we get b = 2 and c = -8 ( solved c just for fun guess :) ) .
hope this helps :)
-audrey <3