Natali Belska
Просветленный
(36291)
3 года назад
(ab/(a-b) + a) * (ab/(a+b) - a) : a^2*b^2/(a^2-b^2) =
= [ab + a*(a-b)]/(a-b) * [ab - a*(a-b)]/(a+b) * (a^2 - b^2)/a^2*b^2 =
= (ab+a^2-ab)/(a-b) * (ab-a^2+ab)/(a+b) * (a^2 - b^2)/a^2*b^2 =
= a^2*(-a^2)/(a+b)(a-b) * (a+b)(a-b)/a^2*b^2 =
= a^2/a^2 * (-a^2) * (a+b)(a-b)/(a+b)(a-b) * 1/b^2 =
= 1 * (-a^2) * 1 * 1/b^2 = - (a/b)^2 =
= - (V5/V2)^2 = - 5/2