Subtract:
[tex]\[ \left(9a^2 - 7b + 3c^3 - 4\right) - \left(6a^2 + 6b - 3c^3 - 4\right) \][/tex]

A. [tex]\( 15a^2 - b - 8 \)[/tex]

B. [tex]\( 3a^2 - 13b + 6c^3 \)[/tex]

C. [tex]\( 3a^2 - b \)[/tex]

D. [tex]\( 3a^2 + 13b - 6c^3 \)[/tex]



Answer :

To subtract the expressions [tex]\((9a^2 - 7b + 3c^3 - 4)\)[/tex] and [tex]\((6a^2 + 6b - 3c^3 - 4)\)[/tex], follow these steps:

1. Align the like terms: Place the two expressions in such a way that like terms are aligned for easy subtraction.

Original expressions:
[tex]\[ (9a^2 - 7b + 3c^3 - 4) - (6a^2 + 6b - 3c^3 - 4) \][/tex]

2. Distribute the negative sign: Distribute the negative sign across the second set of parentheses:

[tex]\[ 9a^2 - 7b + 3c^3 - 4 - 6a^2 - 6b + 3c^3 + 4 \][/tex]

3. Combine like terms:

- Coefficients of [tex]\(a^2\)[/tex]:
[tex]\[ 9a^2 - 6a^2 = 3a^2 \][/tex]

- Coefficients of [tex]\(b\)[/tex]:
[tex]\[ -7b - 6b = -13b \][/tex]

- Coefficients of [tex]\(c^3\)[/tex]:
[tex]\[ 3c^3 + 3c^3 = 6c^3 \][/tex]

- Constants:
[tex]\[ -4 + 4 = 0 \][/tex]

4. Write the resulting expression:
[tex]\[ 3a^2 - 13b + 6c^3 \][/tex]

Therefore, the simplified expression after subtracting [tex]\((6a^2 + 6b - 3c^3 - 4)\)[/tex] from [tex]\((9a^2 - 7b + 3c^3 - 4)\)[/tex] is:
[tex]\[ 3a^2 - 13b + 6c^3 \][/tex]

So, the correct choice is:
[tex]\[ \boxed{3a^2 - 13b + 6c^3} \][/tex]