(4x - 5)^2 = (4x - 5) (4x - 5)
y^2 - 25 = y^2 - 5^2 = (y - 5) (y + 5)
7x(a - b) - 9(a - b) = (7x - 9) (a - b)
(4x - 5)^2 = (4x - 5) (4x - 5)
y^2 - 25 = y^2 - 5^2 = (y - 5) (y + 5)
7x(a - b) - 9(a - b) = (7x - 9) (a - b)