Ok this is kind of silly to ask but i have an equation 12-3x how do i get 3x in the front i know i should know this but can anyone explain

What is the size of the matrix resulting from

Marina baked cookies. she gave 3/4 of the cookies to the scout bake sale. she shared the remaining 6 cookies with her friends. how many cookies did marina bake?

The total ticket sales for a high school basketball game were $2,260. the ticket price for students were $2.25 less than the adult ticket price. the number of adult tickets sold was 230, and the number of student tickets sold was 180. what was the price of an adult ticket?