Answer :
We start with the expression
[tex]$$
(7x^3 - 4x^2) + (2x^3 - 4x^2).
$$[/tex]
1. First, group the like terms. The terms with [tex]$x^3$[/tex] are [tex]$7x^3$[/tex] and [tex]$2x^3$[/tex], and the terms with [tex]$x^2$[/tex] are [tex]$-4x^2$[/tex] and [tex]$-4x^2$[/tex].
2. Combine the [tex]$x^3$[/tex] terms:
[tex]$$
7x^3 + 2x^3 = (7 + 2)x^3 = 9x^3.
$$[/tex]
3. Combine the [tex]$x^2$[/tex] terms:
[tex]$$
-4x^2 - 4x^2 = (-4 - 4)x^2 = -8x^2.
$$[/tex]
4. Therefore, the sum of the polynomials is:
[tex]$$
9x^3 - 8x^2.
$$[/tex]
This corresponds to the option:
[tex]$$
9x^3-8x^2.
$$[/tex]
[tex]$$
(7x^3 - 4x^2) + (2x^3 - 4x^2).
$$[/tex]
1. First, group the like terms. The terms with [tex]$x^3$[/tex] are [tex]$7x^3$[/tex] and [tex]$2x^3$[/tex], and the terms with [tex]$x^2$[/tex] are [tex]$-4x^2$[/tex] and [tex]$-4x^2$[/tex].
2. Combine the [tex]$x^3$[/tex] terms:
[tex]$$
7x^3 + 2x^3 = (7 + 2)x^3 = 9x^3.
$$[/tex]
3. Combine the [tex]$x^2$[/tex] terms:
[tex]$$
-4x^2 - 4x^2 = (-4 - 4)x^2 = -8x^2.
$$[/tex]
4. Therefore, the sum of the polynomials is:
[tex]$$
9x^3 - 8x^2.
$$[/tex]
This corresponds to the option:
[tex]$$
9x^3-8x^2.
$$[/tex]