Question

упростите выражение​

Answer 1

$( frac{a}{a - 4} - frac{a}{a + 4} ) times frac{a + 4}{a} = frac{a(a + 4) - a(a - 4)}{(a + 4)(a - 4)} times frac{a + 4}{a} = frac{a(a + 4) - a(a - 4)}{a(a - 4)} = frac{a {}^{2} + 4a - a {}^{2} + 4a }{a(a - 4) } = frac{8a}{a(a - 4)} = frac{8}{a - 4}$