a) (a + b)n + (a + b)y = (a + b)(n + y)
b) (c - d)m - (c - d)n = (c - d)(m - n)
c) x(2a + b) - 15(2a + b) = (2a + b)(x - 15)
d) (x² - y²) + b(x² - y²) = (x² - y²)(1 + b) = (x - y)(x + y)(1 + b)
e) ab²(xy + z) - (xy + z) = (xy + z)(ab² - 1)
f) a(my - y) - (my - y) = (my - y)(a - 1) = y(m -1)(a - 1)
g) 5x(x + 1) + (x + 1)² = (x + 1)(5x + x + 1) = (x + 1)(6x + 1)
h) (7x + 2)² - 3x(7x + 2) = (7x + 2)(7x + 2 - 3x) = (7x + 2)(4x + 2)
