Answer :

Let's simplify the expression [tex]\(-a(5a - 9)\)[/tex] step by step.

1. Initial Expression:
[tex]\[ -a(5a - 9) \][/tex]

2. Distribute the [tex]\( -a \)[/tex] across the terms within the parenthesis:
[tex]\[ -a \cdot 5a + (-a) \cdot (-9) \][/tex]

3. Multiply each term separately:
- The first term: [tex]\( -a \cdot 5a = -5a^2 \)[/tex]
- The second term: [tex]\( (-a) \cdot (-9) = 9a \)[/tex]

4. Combine these results into a single expression:
[tex]\[ -5a^2 + 9a \][/tex]

5. Express the simplified expression clearly:
[tex]\[ 9a - 5a^2 \][/tex]

Therefore, the original expression [tex]\(-a(5a - 9)\)[/tex] simplifies to [tex]\( 9a - 5a^2 \)[/tex].

Final result:
[tex]\[ -a(5a - 9) = 9a - 5a^2 \][/tex]