Question

Of (x-2) is factor of x3+ax2+bx+16 and b=4a. Find a and b

Answer 1

x=2
f(2)=8+4a+4a×2+16
0=24+12a
12a=-24
a=-2
b=4×(-2)=-8
is your answer

Answer 2

This is lengthy but easy to understand.