What is the coefficient of x in (x3+x2+x+1)(x4−8x3+17x2−23x+14)?
This is defintely not a smart tactice, but let's expand everything.
I won't show all the steps, but we eventually get
x7−7x6+10x5−13x4+8x2−9x+14
Thus, our answer is -9.
Thanks! :)