Answer:
131 in²
Explanation:
Let x represent the length of the painting. Given that The width of a painting is 4 inches less than the length. Hence:
Width = x - 4
The area of painting = length * width = x(x - 4) = x² - 4x
The frame that surrounds the painting is 2 inches wide (at the top and bottom, left and right). Hence the total width of the frame = (x - 4) + 2 + 2 = x, the length of the frame = x + 2 + 2 = x + 4
The area of the frame = length * breath = x(x + 4) = x² + 4x
Given that the area of the frame = 240 in², hence:
x² + 4x = 240
x² + 4x - 240 = 0
x = -17.62 and x = 13.62
Since the length cannot be negative, hence length = x = 13.62 inches
Area of painting = x(x - 4) = 13.62(13.62 - 4) = 131 in²