Given the task, the provided mathematical expression can be formatted for better readability as follows:

[tex]\[
\frac{rs}{3} + \frac{xy}{7}
\][/tex]

[tex]\[
3x^4 + 9x^3 - 4x^5 + 1
\][/tex]

This maintains the integrity of the original content while presenting it in a clearer, more readable manner.



Answer :

Sure! Let's go through each expression step by step.

### Expression 1: [tex]\(\frac{r s}{3}+\frac{x y}{7}\)[/tex]

1. Identify the terms:
- The first term is [tex]\(\frac{r s}{3}\)[/tex].
- The second term is [tex]\(\frac{x y}{7}\)[/tex].

2. Combine the terms:
- Since these terms do not have a common denominator, we simply write them as they are.
- The overall expression remains [tex]\(\frac{r s}{3} + \frac{x y}{7}\)[/tex].

So, the first expression in its simplified form is:
[tex]\[ \frac{r s}{3} + \frac{x y}{7} \][/tex]

### Expression 2: [tex]\(3 x^4 + 9 x^3 - 4 x^5 + 1\)[/tex]

1. Identify the terms:
- The polynomial given is [tex]\(3 x^4 + 9 x^3 - 4 x^5 + 1\)[/tex].

2. Arrange the terms:
- We usually write polynomials in descending order of the powers of [tex]\(x\)[/tex].
- So, we rearrange the terms as [tex]\( -4 x^5 + 3 x^4 + 9 x^3 + 1 \)[/tex].

This polynomial is already simplified and arranged in standard form. Thus, the second expression is:
[tex]\[ -4 x^5 + 3 x^4 + 9 x^3 + 1 \][/tex]

### Summary

The final forms of the given mathematical expressions are:
1. [tex]\(\frac{r s}{3} + \frac{x y}{7}\)[/tex]
2. [tex]\(-4 x^5 + 3 x^4 + 9 x^3 + 1\)[/tex]

These expressions are fully simplified and properly organized.