Question

Pfv preciso dos calculos..

Answer 1

(a-¹ + b-¹)-² = (1/a + 1/b)-² = 1 / (1/a + 1/b)² = 1 / [(1/a)² + 2.(1/a).(1/b) + (1/b)²] = 

= 1 / [1/a² + 2ab + 1/b²] mmc dentro doq tá em parêntese = a².ab.b² = a³.b³

= 1 / [(a.b³ + 2.a².b² + a³.b)/a³.b³]= 

= 1 / [ab³ +2a²b² + a³b)/a³b³]

= 1 / [ab(b² + 2ab + a²]/a³b³] 

= 1 / [(b² + 2ab + a²)/a²b²] 

= 1 / [(a² + 2ab + b²)/a²b²] 

= 1 / [(a+b)²]/(a²b²) 

= 1 / [(a+b)²]/(a²b²) = (a²b²)/(a+b)² 
 a resposta é D