Answer:
P = (x + y)(x - y)(x + 2)(x - 2)
Explanation:
P = -x²y² + x⁴ + 4y² - 4x²
Rewrite the polynomial in descending powers of x and ascending powers of y. Then
P = x⁴ - 4x² - x²y² + 4y²
Remove the common factor from the first two and the last two terms.
P = x²(x² - 4) - y²(x² - 4)
Distribute x² - 4
P = (x² - y²)(x² - 4)
Factor each binomial
P = (x + y)(x - y)(x + 2)(x - 2)