Вправи 101 - 200 » 168 (3-4)

3) 2x/(x^2- y^2 ) : (1/(x^2+ 2xy+ y^2 ) – 1/(y^2- x^2 )) = 2x/(x^2- y^2 ) : (1^(\x-y)/((x+y)^2 ) + 1^(\x+y)/((x+y)(x-y))) = 2x/((x+y)(x-y)) : (x-y+x+y)/((x+y)^2 (x-y)) = (2x • (x+y)^2 (x-y))/((x+y)(x-y) • 2x) = (x+y)/1 = x + y; 4) ((2a-3)/(a^2- 4a+4) – (a-1)/(a^2- 2a)) : (a^2- 2)/(a^3- 4a) = ((2a- 3^(\a))/((a-2)^2 ) – (a- 1^(\a-2))/(a(a-2))) : (a^2- 2)/(a(a^2- 4)) = (a(2a-3)- (a-1)(a-2))/((a-2)^2 • a) : (a^2- 2)/(a(a-2)(a+2)) = (2a^2- 3a-(a^2- 2a-a+2))/(a(a-2)^2 ) • (a(a-2)(a+2))/(a^2- 2) = ((2a^2- 3a- a^2+ 3a-2)a(a-2)(a+2))/(a(a-2)^2 (a^2- 2)) = ((a^2- 2)a(a-2)(a+2))/(a(a-2)^2 (a^2- 2)) = (a+2)/(a-2).