д) 20y^2 + 2a^3 = 2(10y^2 + a^3) = 2(5y√2 + a)(5y√2 - a)
ж) 5x - 5a^2x = 5(x - a^2x) = 5(1 - a^2)x
з) bc^3 - b^3c = bc(c^2 - b^2) = bc(c - b)(c + b)
д) 20y^2 + 2a^3 = 2(10y^2 + a^3) = 2(5y√2 + a)(5y√2 - a)
ж) 5x - 5a^2x = 5(x - a^2x) = 5(1 - a^2)x
з) bc^3 - b^3c = bc(c^2 - b^2) = bc(c - b)(c + b)