F(x)=x-3, what is the value of x if f(x) is equal to 3

How do i do this? i don’t understand

John read the first 114 pages of a novel, which was 3 pages less than 1/3 of the novel. write an equation to determine the total number of pages (p)(p) in the novel.

Helena lost her marbles. but then she found them and put them in 44 bags with mm marbles in each bag. she had 33 marbles left over that didn't fit in the bags.