Question

решительно пож срочно надо очень

Answer 1

$frac{b+4}{b^2+16} *( frac{b+4}{b-4} + frac{b-4}{b+4} )= frac{2}{b-4} \ \ 1) frac{b+4}{b-4} + frac{b-4}{b+4} = frac{(b+4)(b+4)+(b-4)(b-4)}{(b+4)(b-4)} = frac{(b+4)^2+(b-4)^2}{(b+4)(b-4)} = \ \ = frac{b^2+16+8b+b^2+16-8b}{(b-4)(b+4)} = frac{2b^2+32}{(b-4)(b+4)} \ \ 2) frac{b+4}{b^2+16} * frac{2(b^2+16)}{(b-4)(b+4)} = frac{2}{b-4} \ \ \ frac{2}{3.75-4} = frac{2}{-0.25} =-8$