What is the sum of the polynomials?

[tex]\[
(8x^2 - 9y^2 - 4x) + (x^2 - 3y^2 - 7x)
\][/tex]

A. [tex]\(7x^2 - 6y^2 + 3x\)[/tex]
B. [tex]\(9x^2 - 6y^2 + 3x\)[/tex]
C. [tex]\(9x^2 - 12y^2 + 3x\)[/tex]
D. [tex]\(9x^2 - 12y^2 - 11x\)[/tex]



Answer :

To find the sum of the polynomials [tex]\((8x^2 - 9y^2 - 4x)\)[/tex] and [tex]\((x^2 - 3y^2 - 7x)\)[/tex], we need to add the coefficients of the corresponding terms: [tex]\(x^2\)[/tex], [tex]\(y^2\)[/tex], and [tex]\(x\)[/tex].

### Step-by-Step Solution:

1. Identify the coefficients of [tex]\(x^2\)[/tex] terms in both polynomials:
- For the first polynomial: [tex]\(8x^2\)[/tex]
- For the second polynomial: [tex]\(x^2\)[/tex]

Add these coefficients together:
[tex]\[ 8 + 1 = 9 \][/tex]
Hence, the coefficient of [tex]\(x^2\)[/tex] in the resulting polynomial is [tex]\(9\)[/tex].

2. Identify the coefficients of [tex]\(y^2\)[/tex] terms in both polynomials:
- For the first polynomial: [tex]\(-9y^2\)[/tex]
- For the second polynomial: [tex]\(-3y^2\)[/tex]

Add these coefficients together:
[tex]\[ -9 + (-3) = -12 \][/tex]
Hence, the coefficient of [tex]\(y^2\)[/tex] in the resulting polynomial is [tex]\(-12\)[/tex].

3. Identify the coefficients of [tex]\(x\)[/tex] terms in both polynomials:
- For the first polynomial: [tex]\(-4x\)[/tex]
- For the second polynomial: [tex]\(-7x\)[/tex]

Add these coefficients together:
[tex]\[ -4 + (-7) = -11 \][/tex]
Hence, the coefficient of [tex]\(x\)[/tex] in the resulting polynomial is [tex]\(-11\)[/tex].

### Form the Resulting Polynomial:
Combine the results from each step to form the sum of the given polynomials:
[tex]\[ 9x^2 - 12y^2 - 11x \][/tex]

### Final Answer:
The sum of the polynomials [tex]\((8x^2 - 9y^2 - 4x)\)[/tex] and [tex]\((x^2 - 3y^2 - 7x)\)[/tex] is:
[tex]\[ \boxed{9x^2 - 12y^2 - 11x} \][/tex]