1. (x^2 + y)^2 = (x^2 + y) * (x^2 + y)
2. (2c^2 + 3d^2) * (2c^2 + 3d^2)
3. (-a - 1) * (-a - 1)
4. ((x^2 +1) - 2x) * ((x^2 +1) + 2x)
5. ((a + b) - c) * (a + b) + c)
6. x * (1 - x) + y * (1-y) = (x + y) * ((1 - x) + (1 - y))
7. n * (m - k)^3
8. ((m + d) - n) * ((m + d) + n)