Question

__b___ : ___a____ * ab
a^2-ab       a-b   

Answer 1

$frac {b} {a^2-ab} : frac {a}{a-b} * ab=frac {b}{a(a-b)} frac {a-b}{a} *ab =frac {b (a-b) ab}{(a-b)a}=b^2$