Answer:
SINGULAR →PLURAL
1. trabajador →trabajadores
2. inteligente →inteligentes
3. el cuaderno→ los cuadernos
4. una mochila →unas mochilas
5. el lápiz →los lápices (*!!)
Step-by-step explanation:
For a noun that ends in a vowel you add "s."
For a noun that ends in a consonant to be plural you have to add "es".
(*!!) don't forget the acute accent "á" in question #5 →→→ los lápices