A) 20c^2 - 80bc = 20c(c - 4b)
b)3a^3 b - 6a^2 b^2 = 3a^2 b(a - 2b)
v)2x + ac + cx + 2a = 2(a + x) + c(a + x) = (c + 2)(a + x)
g) 3a - 3m - ay + my = 3(a - m) - y(a - m) = (3 - y)(a - m)
d) 2ax + 3by + 6ay + bx = b(3y + x) + 2a(3y + x) = (2a + b)(3y + x)
e) 49y^2 - 14y + 1 = (7y - 1)^2
ж) 9a^2 + 6ab + b^2 = (3a + b)^2
з) 16m^2 - 1 = (4m - 1)(4m + 1)
и) 25y^2 - 64z^2 = (5y - 8z)(5y + 8z)