Hey there!☺
![Answer:\boxed{40}](https://img.qammunity.org/2021/formulas/mathematics/high-school/gmjsjmjylqb3h1oly10f8mzefvixardzxv.png)
![Explanation:](https://img.qammunity.org/2021/formulas/mathematics/high-school/52wuumktrf7929ih69wz4bfv1lq1cmfdck.png)
Elga's age can be represented as "x". If Elga is x years old, then Alvin's age would be represented as "x+9", since Alvin is 9 years older than Elga.
Their combined age is 89. If you were to write that as an equation in terms of "x", you would have the following equation.
![x+x+9=89](https://img.qammunity.org/2021/formulas/mathematics/high-school/y6fb5mtygwfswcafeqbjehs93n2k3fqdm7.png)
Since the question is asking for Elga's age, which is x, you're going to be solving the equation for the value of x.
First add like terms:
![x+x+9=89 \rightarrow 2x+9=89](https://img.qammunity.org/2021/formulas/mathematics/high-school/bl0gwo0pkj5afh42rq1tcqsmse1uan6b76.png)
Subtract both sides by 9 to leave x alone:
![2x+9-9=89-9 \rightarrow 2x=80](https://img.qammunity.org/2021/formulas/mathematics/high-school/uwi4duzi54c88g3hw3q2woobgxebx5d6jh.png)
Divide both sides by 2 to find x:
![(2x)/(2) = (80)/(2) \rightarrow x=40](https://img.qammunity.org/2021/formulas/mathematics/high-school/y1n90vq7pfh0evfbfue0s7pfopn2c4vfdd.png)
Since x is equal to 40, Elga is 40 years old, and Alvin would be 49 years old.
You can also check if the answer is correct by adding their ages.
![40+49=89\ \br \checkmark](https://img.qammunity.org/2021/formulas/mathematics/high-school/pajo84kiyq1fwhou2csqgb3s4nkzfqnaw2.png)
Elga is 40 years old.
Hope this helps!
![\text{-TestedHyperr}](https://img.qammunity.org/2021/formulas/biology/college/gu3hvz39ibpcjq9at1g837tid91sy3vbnn.png)