Вправи 801- 887 » 840

840. Спрости вираз: в) (1/(x+ x√y) + 1/(x- x√y)) : 2/(y-1) = (1-√y+1+√y )/(x(1+ √y)(1- √y)) • (y-1)/2 = (2(y-1))/((1-y)•2x) = –1/x. г) (√a/(√a- √b) – √a/(√a+√b)) • 〖(b- a)〗^2/√ab = (√a (√a+ √b)-√a( √a-√b) )/((√a- √b)(√a+ √b)) • 〖(b- a)〗^2/√ab = (a+ √ab- a+√ab )/(a- b) • 〖(b- a)〗^2/√ab = 〖2√ab(a- b)〗^2/((a- b)• √ab) = 2(a – b).