Hey there!☺
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.
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:
Subtract both sides by 9 to leave x alone:
Divide both sides by 2 to find x:
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.
Elga is 40 years old.
Hope this helps!