Answer :

Sure, let's add the given algebraic expressions step by step:

First, list the expressions:
1. [tex]\(-4xz - 15xy\)[/tex]
2. [tex]\(20xy - 9yz - 16xz\)[/tex]
3. [tex]\(16xy - 24yz - 16xz\)[/tex]
4. [tex]\(-24xyz\)[/tex]
5. [tex]\(5x^2y^2 - 9yz - 20x^2z^2\)[/tex]
6. [tex]\(5xy - 9yz - 20xz\)[/tex]

### Step 1: Combine like terms

Group all terms with [tex]\(xy\)[/tex]:
[tex]\[ -15xy + 20xy + 16xy + 5xy \][/tex]

Group all terms with [tex]\(xz\)[/tex]:
[tex]\[ -4xz - 16xz - 16xz - 20xz \][/tex]

Group all terms with [tex]\(yz\)[/tex]:
[tex]\[ -9yz - 9yz - 24yz - 9yz \][/tex]

Include the remaining terms as they are:
[tex]\[ -24xyz \][/tex]
[tex]\[ 5x^2y^2 \][/tex]
[tex]\[ -20x^2z^2 \][/tex]

### Step 2: Simplify each group

Simplify the coefficients:
- For [tex]\(xy\)[/tex]:
[tex]\[ -15 + 20 + 16 + 5 = 26 \quad \text{So,} \quad 26xy \][/tex]

- For [tex]\(xz\)[/tex]:
[tex]\[ -4 - 16 - 16 - 20 = -56 \quad \text{So,} \quad -56xz \][/tex]

- For [tex]\(yz\)[/tex]:
[tex]\[ -9 - 9 - 24 - 9 = -51 \quad \text{So,} \quad -51yz \][/tex]

### Step 3: Combine all simplified terms

After combining all terms, the resulting expression is:
[tex]\[ 5x^2y^2 - 20x^2z^2 - 24xyz + 26xy - 56xz - 51yz \][/tex]

Therefore, the simplified expression obtained by adding all the given algebraic expressions is:
[tex]\[ 5x^2y^2 - 20x^2z^2 - 24xyz + 26xy - 56xz - 51yz \][/tex]