What will fill in the blank la estudiante trabajadora

Ineed with spanish homework. translation of task: 11. fill out with the correct form of estar or hay 12. fill in fill with the verbs hay, estar and ser.

Which of the following is the first-person singular (yo) form of the verb "to think" in present tense? a. pienso b. penso c. piensa d. pensamos

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