Question

已知分式-6a+18/a²-9的值为正整数,求整数a的值

Answer 1

6a+18/a^2-9

=6(a+3)/(a+3)(a-3)

=6/(a-3)

当a=4 ,值=6;

a=5 ,值=3;

a=6 ,值=2;

a=9 ,值=1;