Achte bitte auf die Klammersetzung!!
a)
(x-8)/(x+16) = (x+16)/(x-8) |*(x+16)*(x-8)
(x-8)^2 = (x+16)^2
x^2-16x+64 = x^2+32x+256 |+16x-256
48x = -192
x = -4
b)
(x+3)/(x-3) = (x+4)/(x-8) |*(x-3)(x-8)
(x+3)(x-8) = (x+4)(x-3)
x^2+3x-8x-24 = x^2-3x+4x-12 |-x^2+5x+12
6x = -12
x = -2
Grüße