Answer:
Error: He added the exponents of the variables. The exponents must be subtracted.
Correct solution:
![w=9x^6y^4](https://img.qammunity.org/2020/formulas/mathematics/middle-school/uk9u3ao6rrpry16vduxvclx248vutue3xo.png)
Explanation:
According the quotient property of exponents, when you divide two powers with equal base, you must subtract the exponents.
Therefore, keeping the property above on mind, you have:
![w=(54x^9y^8)/(6x^3 y^4)\\\\w=9x^((9-3))y^((8-4))](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ku1yc1pmz6zjyrrade3ssqt1ofsda70oid.png)
Therefore, you have that the width of the rectangle is the shown below:
![w=9x^6y^4](https://img.qammunity.org/2020/formulas/mathematics/middle-school/uk9u3ao6rrpry16vduxvclx248vutue3xo.png)