Ser and estar both mean “to be”. Ser is used to talk about WHAT something is. This includes date, occupation, characteristics, time, origin, and relationship. Estar is used to talk about HOW something is. This includes position, location, action, condition, and emotion.
Examples of ser:
-Yo soy alta.
-Ella es inteligente.
Examples of estar:
-El está triste.
-Estoy mirando la tele.
Answer:
te ayudaría pero la suma de todas las fuerzas es igual a 0
Buenas noches is how you say it.