'Applied' in the Bible

I applied my mind to seek and to search by wisdom all that is done under the heavens. It [is] a grievous task God has given to {humans}.

I saw all this as I applied my heart to all the deeds done under the sun: {sometimes those in authority harm others}.

I applied my mind to know wisdom and to understand the business that is done on earth--how neither day nor night one's eyes see sleep.