Question

Упростите выражение

Answer 1

$frac{a+12}{4a+16}- frac{a+4}{4a-16}- frac{19}{16-a^{2}}= frac{a+12}{4(a+4)}- frac{a+4}{4(a-4)}+ frac{19}{(a-4)(a+4)} = frac{a^{2}-4a+12a-48-a^{2}-4a-4a-16+76}{4(a-4)(a+4)}= frac{12}{4(a^{2}-16)}= frac{3}{a^{2}-16}$