Question

Найдите значение выражения:

Answer 1

$frac{b+4}{b^{2}+16}* frac{(b+4)^{2}+(b-4)^{2}}{b^{2}-16}= frac{(b+4)*(b^{2}+8b+16+b^{2}-8b+16)}{(b^{2}+16)(b^{2}-16)}= frac{(b+4)(2b^{2}+32)}{(b^{2}+16)(b^{2}-16)}= \ frac{(b+4)*2(b^{2}+16)}{(b^{2}+16)(b^{2}-16)} = frac{b+4}{(b-4)(b+4)}= frac{1}{b-4} \ b=3,75 \ frac{1}{3,75-4}= frac{1}{-0,25} =-4$