Question

which expression is equivalent to b^-2/ab^-3 assume a=0 b=0
Answers:
a/b^5
1/ab^5
a^3b/1
b/a

Answer 1

b^-2/ab^-3 = b^-2/b^-3 x 1/a = b^[-2-(-3)] x 1/a = b x 1/a = b/a

Answer 2

we have

$\frac{b^{-2}} {ab^{-3}}$

we know that

$\frac{b^{-2}} {ab^{-3}} =(\frac{1}{b^{2}})( \frac{1}{a})( b^{3})\\ \\=\frac{b^{3}}{ab^{2}} \\ \\= \frac{b}{a}$

therefore

the answer is the option

$\frac{b}{a}$