The length of a rectangle is three centimeters more than twice the width. the perimeter is 78 centimeters. define a variable and write and solve an equation to find out how long and wide the rectangle is? i need to find the length? how?

Amira is painting a rectangular banner 2 1/4 yards wide. the banner will have a blue background. amira has enough paint to cover 1 1/2 square yards of the wall. the school colors are blue and yellow, so amira wants to add yellow rectangles on the left and right sides of the blue rectangle. the yellow rectangles will each be 3/4 yards wide and the same height as the blue rectangle. what will be the total area of the two yellow rectangles?