Question

please help! if anybody is good at equivalent polynomial expressions please help!!

Answer 1

The answer you have highlighted is correct.  Here is why

$( \frac{ b^{2}-10 }{b^{2}-9})( \frac{b - 3}{b + 10})$
$\frac{(b+10)(b-10)}{(b+3)(b-3)}( \frac{b-3}{b+10})$ - Factor the top
$\frac{b-10}{b+3}$ - the (b-3)'s and (b+10)'s cancel out since on top and bottom.