Let's simplify the given expression step-by-step.
The expression we need to simplify is:
[tex]\[ (9x^2 + 10x + 4) - (9x^2 + 5x - 1) \][/tex]
1. Distribute the negative sign to the terms inside the second set of parentheses:
[tex]\[ 9x^2 + 10x + 4 - 9x^2 - 5x + 1 \][/tex]
2. Combine like terms:
- Combine the [tex]\(x^2\)[/tex] terms:
[tex]\[ 9x^2 - 9x^2 = 0 \][/tex]
- Combine the [tex]\(x\)[/tex] terms:
[tex]\[ 10x - 5x = 5x \][/tex]
- Combine the constant terms:
[tex]\[ 4 + 1 = 5 \][/tex]
3. Simplify the expression:
[tex]\[ 0 + 5x + 5 \][/tex]
[tex]\[ = 5x + 5 \][/tex]
Therefore, the simplified form of the expression is:
[tex]\[ \boxed{5x + 5} \][/tex]
So, the correct answer is:
[tex]\[ \text{B. } 5x + 5 \][/tex]
