What are the answers to these math problems...??? ( factoring )

Question

1) m^2 2mn n^2 - t^2

2) 9 - x^2 - 10xy - 25y^2

3) mx my - nx - ny

4) 16c^2 - 4d - 4d^2 -1

Answer 1

1) Did you want a t in this problem?

m² + 2mn + n² - t² = (m + n)² - t²

2)  9 - x² - 10xy - 25y² = (3 - x - 5y)(x + 5y + 3)

3) mx + my - nx - ny = (m - n)(x + y)

4)  16c² - 4d - 4d² - 1 = (4c + 2d + 1)(4c - 2d - 1)

Hope this helps you!