A framed picture has length 50 cm and width 40 cm . The picture itself has area 1344 cm^2. How far is it from the edge of the picture to the edge of the frame if thid didtance is uniform around the picture ?

if the width of the frame is w, the dimensions of the picture are 50-2w and 40-2w (subtract w on each side). So, since we know the area of the picture,