Question

先化简,再求值:a+2分之a-a-1分之1除以a的平方-2a+1分之a+2,其中,a=2根号3-2

Answer 1

a/(a+2)-1/(a-1)÷(a+2)/(a²-2a+1)

=a/(a+2)-1/(a-1)×(a-1)²/(a+2)

=a/(a+2)-(a-1)/(a+2)

=1/(a+2)

=1/(2√3-2+2)

=1/2√3

=√3/6