Question

what must be added to 3n3-2n2+5n+1so that the sum be n3- 2n 2 +4n-1

Answer 1

let x is to be added
so, According to question

(3n³ - 2n² + 5n + 1) + x = n³ - 2n² +4n -1

=> x = n³ -2n² +4n -1 -(3n³ -2n² +5n+1)

=> x= n³ - 2n² +4n-1 - 3n³ + 2n² -5n - 1

=> x = -2n³ -n -2

hence, -2n³ - n- 2 must be added.