Answer:
x⁴ - 8x² + 9
Step-by-step explanation:
The Area of the smallest square is A1 = x . x = x²
The Area of the second square is A2 = ( x² - 3 )(x² - 3)
A2 = x⁴ - 3x² - 3x² + 9
A2 = x⁴ - 6x² + 9
The Area of the Shaded shape is A2 - A1
x⁴ - 6x² + 9 - x²
x⁴ - 8x² + 9