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