Question

9b-1/b^2-9 - 6b-10/b^2-9 при b=4,5

Answer 1

$frac{9b-1}{b^{2}-9}-frac{6b-10}{b^{2}-9} =frac{9b-1-6b+10}{b^{2}-9} =frac{3b+9}{b^{2}-9} =frac{3(b+3)}{(b-3)(b+3)} =frac{3}{b-3}$

$frac{3}{4.5-3}=frac{3}{1.5}=2$