Answer :

To solve the problem of subtracting the polynomial [tex]\( 9a^2 - 6a + 5 \)[/tex] from [tex]\( 10a^2 + 3a + 25 \)[/tex], follow these steps:

### Step-by-Step Solution:

1. Write down the polynomials:

[tex]\[ 10a^2 + 3a + 25 \][/tex]
[tex]\[ 9a^2 - 6a + 5 \][/tex]

2. Set up the subtraction:

[tex]\[ (10a^2 + 3a + 25) - (9a^2 - 6a + 5) \][/tex]

Distribute the negative sign to the second polynomial:

[tex]\[ 10a^2 + 3a + 25 - 9a^2 + 6a - 5 \][/tex]

3. Combine like terms:

- Combine the [tex]\( a^2 \)[/tex] terms:
[tex]\[ 10a^2 - 9a^2 = a^2 \][/tex]

- Combine the [tex]\( a \)[/tex] terms:
[tex]\[ 3a + 6a = 9a \][/tex]

- Combine the constant terms:
[tex]\[ 25 - 5 = 20 \][/tex]

4. Write the resulting polynomial in standard form:

[tex]\[ a^2 + 9a + 20 \][/tex]

Therefore, the polynomial obtained after subtracting [tex]\( 9a^2 - 6a + 5 \)[/tex] from [tex]\( 10a^2 + 3a + 25 \)[/tex] is:
[tex]\[ \boxed{a^2 + 9a + 20} \][/tex]