What must be subtracted from x3−3x2+5x−1 to get 2x3+x2−4x+2 ?
Let ′y′ be the term that is to be subtracted from x3−3x2+5x−1
Then, (x3−3x2+5x−1)−y=2x3+x2−4x+2
⇒y=(x3−3x2+5x−1)−(2x3+x2−4x+2)
x3−3x2+5x−1
2x3+ x2−4x+2
− − + − –––––––––––––––––––––––
−x3−4x2+9x−3