What are the 5 AR endings? (spanish)

Achemist mixes 4 liters of one acid solution with 10 liters of a 40% solution, resulting in a 30% acid solution. what is the value of x, the acid concentration of the first solution

Spanish- imagine you’re a teacher and your classroom is really cluttered. in a note to the janitor, tell him a few things that you don’t need and a few things to keep in your classroom. be sure to mention at least 7 total classroom objects. be sure to mention why you do or do not need those objects.

Es necesario hablar con nuestro gobernador de dos muy importantes. a. asuntos b. la injusticia c. la necesidad d. el medio ambiente !