If 2y3+y2−2y−1=(x+a)(x−b)(cx+d).Find a+b+c+d
We have, 2y3+y2−2y−1
wecanclearlyseey=1is oneofthezeroes
=(y−1)(2y2+3y+1)=(y−1)[2y2+2y+y+1]
=(y−1)[2y(y+1)+1(y+1)]
=(y−1)(y+1)(2y+1)
=(y+1)(y−1)(2y+1)
∴a=1,b=1,c=2andd=1
∴a+b+c+d=5