Skróć ułamki;podaj konieczne założenia a) x^2-14x+49/49-x^2 b)2x^3 - 16/x^2+2x+4 Z góry dziękuję.

x²-14x+49 = (7-x)² 49-x²=(7-x)(7+x) (7-x)(7-x)/(7-x)(7+x)=(7-x)/(7+x), x≠-7

a) (x² - 14x + 49)/(49 - x²) = (x - 7)²/[- (x² - 49)] = = -(x - 7)²/(x - 7)(x + 7) = = - (x - 7)/(x + 7) = = (7 - x)/(x + 7) D: x∈ R {- 7, 7} b) (2x³ - 16)/(x² + 2x + 4) = 2(x³ - 8)/(x + 2)² = = 2(x + 2)(x² - x + 4)/(x + 2)² = = 2(x² - x + 4)/(x + 2) D: x∈ R {- 2 }