А2-в2/ав / (1/в - 1/а)

Question

А2-в2/ав / (1/в - 1/а)

Answer 1

(a²-b²)/ab : (1/b -1/a) = (a-b)(a+b)/ab : (a-b)/ab = (a-b)(a+b)/ab *ab/(a-b)=a+b