Question

What is the sum of the polynomials?

(7x3 – 4x2) + (2x3 – 4x2)

a)5x3
b)9x3
c)5x3 – 8x2
d)9x3 – 8x2

Answer 1

(7x3 – 4x2) + (2x3 – 4x2) = 9x3 – 8x2

Answer 2

If you have to find the sum of the polynomials
`(7x^3 - 4x^2) + (2x^3 - 4x^2)=7x^3-4x^2+2x^3-4x^2`, then you have:

1. group all terms that have equal degrees

`7x^3+2x^3 \text{ and } -4x^2-4x^2`.

2. Add the coefficients near terms of equal degree

7+2=9,

-4-4=-8.

3. Write the sum as
`9x^3-8x^2`.

Answer: correct choice is D.