Respuesta :

Kaikerscupcake
Hey there! :D

87= 2x+x <== let x equal Elga's age. 

Since Alvin's is 2 times Elga's, then you can represent that by 2x. They add up to 87. 

87= 2x+x

87= 3x

Divide both sides by 3. 

x=29

Elga is 29. 

I hope this helps!
~kaikers