a) (a+b) / (a^2 - b^2) = (a+b) / ((a-b)(a+b)) = 1 / (a-b)в) (а^2 - 1) / (ab - b) = (а^2 - 1) / b(a-1)г) (ab - 3a) / (b^2 - 9) = a(b - 3) / ((b+3)(b-3)) = a / (b + 3)д) (x^2 - y^2) / (x^2 + 2xy + y^2) = (x-y)(x+y) / (x+y)^2 = (x-y) / (x+y)е) (a^2 - 2ab + b^2) / (a^2 - b^2) = (a-b)^2 / ((a-b)(a+b)) = a-b / (a+b)
a) (a+b) / (a^2 - b^2) = (a+b) / ((a-b)(a+b)) = 1 / (a-b)
в) (а^2 - 1) / (ab - b) = (а^2 - 1) / b(a-1)
г) (ab - 3a) / (b^2 - 9) = a(b - 3) / ((b+3)(b-3)) = a / (b + 3)
д) (x^2 - y^2) / (x^2 + 2xy + y^2) = (x-y)(x+y) / (x+y)^2 = (x-y) / (x+y)
е) (a^2 - 2ab + b^2) / (a^2 - b^2) = (a-b)^2 / ((a-b)(a+b)) = a-b / (a+b)