You and your friend are painting the walls in your apartment. you estimate that there is 1000 square feet of space to be painted. you paint at a rate of 4 square feet per minute and your friend paint at a rate of 3 square feet per minute. your friend shows up to you paint 45 minutes after you've already started painting
a. write an equation that gives the total number of square feet y as a function of the number of minutes x it takes to paint all the walls
b. how long will it take you and your friend finish painting? round your answer to the nearest minute.