Question

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

Z góry dziękuję.

Answer 1

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

Answer 2

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 }