Resposta :
Alternativa A:[tex]2x + y/3 = 20\\[/tex]
[tex]Marcia = x\\\\Carlos = y\\\\O\ dobro\ de\ Marcia = 2x\\\\ A\ terca\ parte\ de\ Carlos = y/3\\\\2x + y/3 = 20\\[/tex]
Veja mais em:
https://brainly.com.br/tarefa/25642786
https://brainly.com.br/tarefa/96704
![Ver imagem SOCRATESA](https://pt-static.z-dn.net/files/da5/ec4a92502c5e455d6960f08a1dac532c.jpg)