Persiapan UN 2017 Diutamakan siswa - siswi SMP Gunakanlah cara / langkah yang baik

(1/(1+x)).(1-x)³.(x+1/x-1)²
= (x+1)²/(1+x) . (1-x)³/(x-1)²
= (x+1) . -(x-1)(x-1)²/(x-1)²
= -(x+1).(x-1)
= - ( x² - 1)
= 1 - x²

(1/1+x) . (1/1-x)^-3 . (x-1/x+1)^-2
=(1/1+x) . (1-x)^3 . (x+1/x-1)^2
=(x+1) . (1-x)^3 . (1/x-1)^2
=(x+1) . -(x-1)(x-1)^2 / (x-1)^2
=(x+1) . (1 - x)
=1-x^2