Question

分式的混合运算,帮个忙,

Answer 1

x²-x-1=0,x²=x+1

[(x-1)/x-(x-2)/(x+1)]÷[(2x²-x)/(x²+2x+1)]

=[(x²-1-x²+2x)/x(x+1)]÷[x(2x-1)/(x+1)²]

=[(2x-1)/x(x+1)]*[(x+1)²/x(2x-1)]

=[1/x]*[(x+1)/x]

=(x+1)/x²...代入(x²=x+1)

=(x+1)/(x+1)

=1