Answer :

To solve the inequalities [tex]\( -10 < -x - 9 \)[/tex] and [tex]\( -x - 9 \geq -15 \)[/tex], let's tackle each inequality step-by-step.

### First Inequality: [tex]\( -10 < -x - 9 \)[/tex]
1. Add 9 to both sides to isolate the term with [tex]\( x \)[/tex]:
[tex]\[ -10 + 9 < -x - 9 + 9 \][/tex]
2. Simplify the inequality:
[tex]\[ -1 < -x \][/tex]
3. Multiply both sides by [tex]\(-1\)[/tex] to solve for [tex]\( x \)[/tex], remembering to reverse the inequality:
[tex]\[ 1 > x \][/tex]
This can also be written as:
[tex]\[ x < 1 \][/tex]

### Second Inequality: [tex]\( -x - 9 \geq -15 \)[/tex]
1. Add 9 to both sides to isolate the term with [tex]\( x \)[/tex]:
[tex]\[ -x - 9 + 9 \geq -15 + 9 \][/tex]
2. Simplify the inequality:
[tex]\[ -x \geq -6 \][/tex]
3. Multiply both sides by [tex]\(-1\)[/tex] to solve for [tex]\( x \)[/tex], remembering to reverse the inequality:
[tex]\[ x \leq 6 \][/tex]

### Combining the Results
Now we combine the results of both inequalities:
- From the first inequality: [tex]\( x < 1 \)[/tex]
- From the second inequality: [tex]\( x \leq 6 \)[/tex]

The solution is all values of [tex]\( x \)[/tex] that satisfy both conditions:
[tex]\[ x < 1 \quad \text{and} \quad x \leq 6 \][/tex]

Since [tex]\( x \)[/tex] must satisfy [tex]\( x < 1 \)[/tex], which is a stricter condition than [tex]\( x \leq 6 \)[/tex], the combined solution is:
[tex]\[ x < 1 \][/tex]

Therefore, the final solution to the system of inequalities is:
[tex]\[ \boxed{x < 1} \][/tex]