Question

(2cos60度+a-2分之3)除a的平方-4分之a+tan45度

Answer 1

(2cos60度+a-2分之3)除a的平方-4分之a+tan45度

=(a+1)/(a²-4) / (2*(1/2)+3/(a-2))

=(a+1)/(a²-4) / ((a-2+3)/(a-2))

=(a+1)/(a²-4) / (a+1)/(a-2)

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

=1/(a+2)