1) 4a^2-b^2+2a-b

4a^2 - b^2 + 2a - b = (2a + b)(2a - b) + 1(2a - b) = (2a - b)(2a + 1)

2) 4b^2-4ab+a^2-m^2

4b^2 - 4ab + a^2 - m^2 = (2b - a)^2 - m^2 = (2b - a - m)(2b - a + m)