Plz someone help i have no idea how to do this

Can you me conjugate this sentence of doubt using the subjunctive mood? “mis padres dudan que yo (hacer) toda mi tarea cada noche.”

Which form is the correct form? the clock is on the wall. el reloj estás en la pared. el reloj estuvo en la pared. el reloj es en la pared. el reloj está en la pared.

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