Answer:
The correct form of the adjective, in each case, is
1. La abuela es vieja.
2. La abuela es trabajadora.
Step-by-step explanation:
In Spanish, an adjective could be in two forms:
1. Gender.
- Male.
- Female.
2. Number.
- Singular.
- Plural.
This forms can be combined: singular female (vieja, trabajadora), singular male (viejo, trabajador), plural female (viejas, trabajadoras), plural male (viejos, trabajadores), then, now you know what is the correct form in each case, you must see the form of the substantive: "abuela" is a substantive singular and female, for that reason, you must use the forms "vieja, trabajadora".