Question

(x^2+2x-8)/(x^3+2x^2+x)/{(x-2)/x .(x+4)/(x+1) 其中x=4/5

Answer 1

(x^2+2x-8)/(x^3+2x^2+x)/{(x-2)/x .(x+4)/(x+1)

=(x+4)(x-2)/[x(x+1)^2]/{(x+4)(x-2)/[x(x+1)]}

=1/[x(x+1)^2]/{1/[x(x+1)]}

=1/[x(x+1)^2][x(x+1)]

=1/(x+1)

=1/(1+4/5)

=5/9