Answer :

Certainly! Let's simplify the expression [tex]\((x + y + z)^3 - (x - y - z)^3\)[/tex].

Step-by-Step Solution:

1. Write down the given expression:
[tex]\[ (x + y + z)^3 - (x - y - z)^3 \][/tex]

2. Expand both cubes separately:
[tex]\[ (x + y + z)^3 = x^3 + y^3 + z^3 + 3x^2y + 3x^2z + 3y^2x + 3y^2z + 3z^2x + 3z^2y + 6xyz \][/tex]
[tex]\[ (x - y - z)^3 = x^3 - y^3 - z^3 - 3x^2y - 3x^2z + 3y^2x + 3y^2z + 3z^2x + 3z^2y - 6xyz \][/tex]

3. Subtract the second expansion from the first:
[tex]\[ (x + y + z)^3 - (x - y - z)^3 = [x^3 + y^3 + z^3 + 3x^2y + 3x^2z + 3y^2x + 3y^2z + 3z^2x + 3z^2y + 6xyz] - [x^3 - y^3 - z^3 - 3x^2y - 3x^2z + 3y^2x + 3y^2z + 3z^2x + 3z^2y - 6xyz] \][/tex]

4. Combine like terms:
[tex]\[ (x + y + z)^3 - (x - y - z)^3 = x^3 + y^3 + z^3 + 3x^2y + 3x^2z + 3y^2x + 3y^2z + 3z^2x + 3z^2y + 6xyz - x^3 + y^3 + z^3 + 3x^2y + 3x^2z - 3y^2x - 3y^2z - 3z^2x - 3z^2y + 6xyz \][/tex]

5. Notice that many terms cancel each other out:
[tex]\[ = 2y^3 + 2z^3 + 6x^2y + 6x^2z - (- 6y^2x - 6y^2z - 6z^2x - 6z^2y + 12xyz) \][/tex]

6. Rewrite the simplified expression:
[tex]\[ = (-x + y + z)^3 + (x + y + z)^3 \][/tex]

Therefore, the simplified form of [tex]\((x + y + z)^3 - (x - y - z)^3\)[/tex] is:
[tex]\[ (-x + y + z)^3 + (x + y + z)^3 \][/tex]