Simplify the following expression:

[tex]\[
\frac{11}{3(x-5)} - \frac{x+1}{3x}
\][/tex]

Simplify the following expression:

[tex]\[
\frac{-x^2 + ? x + ?}{x^2 + x}
\][/tex]



Answer :

To simplify the given expressions, let's tackle them one by one in detail.

Expression 1:
[tex]\[ \frac{11}{3(x-5)} - \frac{x+1}{3x} \][/tex]

1. Combine the fractions: The common denominator for the fractions is [tex]\(3x(x - 5)\)[/tex].

- The first fraction, [tex]\(\frac{11}{3(x-5)}\)[/tex], needs to be multiplied by [tex]\(x/x\)[/tex] to get the common denominator:
[tex]\[ \frac{11x}{3x(x-5)} \][/tex]

- The second fraction, [tex]\(\frac{x+1}{3x}\)[/tex], needs to be multiplied by [tex]\((x-5)/(x-5)\)[/tex] to get the common denominator:
[tex]\[ \frac{(x+1)(x-5)}{3x(x-5)} = \frac{x^2 - 4x - 5}{3x(x-5)} \][/tex]

2. Subtract the second fraction from the first:
[tex]\[ \frac{11x}{3x(x-5)} - \frac{x^2 - 4x - 5}{3x(x-5)} \][/tex]

Combine the numerators over the common denominator:
[tex]\[ \frac{11x - (x^2 - 4x - 5)}{3x(x-5)} \][/tex]

3. Distribute and combine like terms in the numerator:
[tex]\[ 11x - x^2 + 4x + 5 = -x^2 + 15x + 5 \][/tex]

So, the simplified form of the first expression is:
[tex]\[ \frac{-x^2 + 15x + 5}{3x(x-5)} \][/tex]

Expression 2:
[tex]\[ -x^2 \][/tex]

This expression is already simplified.

Thus, the simplified forms of the given expressions are:
[tex]\[ \frac{-x^2 + 15x + 5}{3x(x-5)} \quad \text{and} \quad -x^2 \][/tex]