Respuesta :
Answer:
sonja has 6 books
Step-by-step explanation:
let m = amount of books sonja has
2m+m=18
combine like terms
3m=18
divide
m=6
sonja has 6 books because alfronzo has twice as much which means he has 12 books and that’s because we multipled sonja’s amount of books with 2 and added 12+6 = 18 (the amount of all their books together)