Polynomial problems...............................................

Question

(1)
Add or Subtract
(9x^4+7x^2-6x-15)+(3x^3-7x^2+6x-15

(2)
Add or Subtract
(9x^3+x^2-x-13)-(9x^3+x^2-x-13)

(3)
Add or Subtract
(9m^4n^2-13m^3n^3+11m^2n^4)+(-4m^2-n^4-3m^4n^2-m^3n^3)

(4)
Add or Subtract
(22x^3y^9-21x^6y^4-7x^8y^2)-(22x^3y^9-21x^6y^4-7x^8y^2)

(5)
Find the missing polynomial
(2x^3-4x^2-7x+19)+ ? =x^2+3x+24

10/20/2013 | Math from Long Beach, CA | 1 Answer | 0 Votes

Answer 1

1. (9x^4 + 7x^2 - 6x - 15) + (3x^3 - 7x^2 + 6x - 15) = 9x^4 + 3x^3 - 30
(9x^4+7x^2-6x-15) - (3x^3-7x^2+6x-15) = 9x^4 - 3x^3 +14x^2 - 12x

2. I hope I am interpreting this correctly

(9m⁴n² - 13m³n³ + 11m²n⁴) +(-4m²-n⁴-3m⁴n²-m³n³) = 6m⁴n² - 14m³n³ + 7m²n⁴ - n⁴
(9m⁴n² - 13m³n³ + 11m²n⁴) - (-4m² - n⁴ - 3m⁴n² - m³n³)= 12m⁴n² -12m3n³ + 15m²n⁴ + n⁴

3. and 4. Dear math student from altadena, CA: now that you've seen how to work a couple of these, why not try the next two on your own. If you run into any difficulty, send me a message and I'll help you.

5. (2x³ - 4x² -7^x +19) + ? = (x² + 3x +24)

You can treat the question mark just as if it were some other variable.

Therefore

? = (x² + 3x +24) - (2x³ - 4x² -7x +19)

? = -2x³ +5x² +10x +5