What should be added to x2+6x−18 to get 3x3+x2+16?
Grouping the like terms together we get, y=3x3+(x2−x2)−6x+(16−18) ⇒ y=3x3−6x−2 Hence, the expression to be added is 3x3−6x−2.
What should be added to x2+3x−8 to get x2+x+6?
What must be added to(x3+3x−8) to get (3x3+x2+6)?