Помогите! !!!!!!!!!!!!!
B^2 + ab - 2a^2 - b + a = b^2 - a^2 + ab - a^2 - b + a = (b - a)*(b + a) + + a*(b - a) - (b - a) = (b - a)*(b +a + a - 1) = (b - a) * (2a + b - 1) Ответ. (b - a) * (2a + b - 1)