What must be subtracted from (x3−3x2+5x−1) to get (2x3+x2−4x+2) ?
−x3−4x2+9x−3
Let the unknown be =y
(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
(−) (−) (+) (−)
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−x3−4x2+9x−3
So we have to subtract (−x3−4x2+9x−3) to get the required value.