Question

The sum of the polynomials 6x3 + 8x2 – 2x + 4 and 10x3 + x2 + 11x + 9 is 16x^3 + 9x^2 + 13x + 13 16x^3 + 9x^2 + 9x + 13 16x^3 + 7x^2 - 9x + 13 . Adding 3x – 2 to this sum gives a sum of 16x^3 + 9x^2 + 16x + 15 16x^3 + 9x^2 + 12x + 11 16x^3 + 9x^2 – 7x + 15 .

Answer 1

`16x^(3) +9x^(2) +9x+13`

`16x^(3) +9x^(2) +12x+11`

Explanation:

We are given two polynomials:

`6x^(3) +8x^(2) -2x+4` and
`10x^(3) +x^(2)+11x+9`

Add these polynomials

`6x^(3) +8x^(2) -2x+4+10x^(3) +x^(2)+11x+9`

`16x^(3) +9x^(2) +9x+13`

Thus Option B of part a is correct

Now we are asked to add 3x-2 to this result :

`16x^(3) +9x^(2) +9x+13+3x-2`

`16x^(3) +9x^(2) +12x+11`

Thus the answer is
`16x^(3) +9x^(2) +12x+11`

Hence option B of part b is correct