Let, Matt's age be x years and Emily's age be y years.
Matt is 9 years older than twice Emily’s age .
It can be written as,
![x=2y+9\ldots\ldots\ldots\ldots(1)](https://img.qammunity.org/2023/formulas/mathematics/college/9bzfhavo62pnphums7xw28s1gczyk3rzf0.png)
And sum of their ages is 90
![x+y=90\ldots\ldots\ldots\ldots\text{.}(2)](https://img.qammunity.org/2023/formulas/mathematics/college/3qfpikiasc19hoj72bb19u47oefhrn4jna.png)
Put the value of x from equation (1) in equation (2).
![\begin{gathered} x+y=90 \\ (2y+9)+y=90 \\ 3y=81 \\ y=27 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/uqx6m7o66yu2nritiinmy2q6e8tl6l0q9q.png)
Put the value of y in equation (1),
![\begin{gathered} x=2y+9 \\ x=2(27)+9 \\ x=63 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/5kis6r8t6n418n568izezab64hapkckn6f.png)
Hence, the Matt's age is x= 63 years and Emily's age is y=27 years.