High School

What is the simplest form of [tex]\left(4x^3 + 6x - 7\right) + \left(3x^3 - 5x^2 - 5x\right)[/tex]?

A. [tex]7x^3 - 5x^2 - x - 7[/tex]
B. [tex]7x^3 - 5x^2 + x - 7[/tex]
C. [tex]7x^3 + x^2 - 5x - 7[/tex]
D. [tex]7x^6 - 4x^2 - 7[/tex]

Answer :

To simplify the expression [tex]\((4x^3 + 6x - 7) + (3x^3 - 5x^2 - 5x)\)[/tex], follow these steps:

1. Combine Like Terms:

- For [tex]\(x^3\)[/tex] terms:
- Add the coefficients of the [tex]\(x^3\)[/tex] terms from both polynomials. We have:
[tex]\[
4x^3 + 3x^3 = 7x^3
\][/tex]

- For [tex]\(x^2\)[/tex] terms:
- Combine the coefficients of the [tex]\(x^2\)[/tex] terms. Note that there is no [tex]\(x^2\)[/tex] term in the first polynomial, so we consider it as [tex]\(0x^2\)[/tex]:
[tex]\[
0x^2 - 5x^2 = -5x^2
\][/tex]

- For [tex]\(x\)[/tex] terms:
- Combine the coefficients of the [tex]\(x\)[/tex] terms:
[tex]\[
6x - 5x = 1x
\][/tex]

- For constant terms:
- Add the constant numbers:
[tex]\[
-7 + 0 = -7
\][/tex]

2. Write the Simplified Expression:

Combine all the results from above:
[tex]\[
7x^3 - 5x^2 + x - 7
\][/tex]

Thus, the simplest form of the given expression is [tex]\(7x^3 - 5x^2 + x - 7\)[/tex].

So, the correct answer is B. [tex]\(7x^3 - 5x^2 + x - 7\)[/tex].