Work out a - 2b as a column vector

Can some one me with these questions

Agroup of randomly selected members of the foodies food club were asked to pick their favorite type of food. the bar graph below shows the results of the survey. there are 244 members in the foodies.

Graph the system of equations on your graph paper to answer the question. {y=−x+4y=x−2 what is the solution for the system of equations? enter your answer in the boxes.