Question

Se A=x-y/xy, x= 2/5 e y= 1/2, então A é igual a ?

Answer 1

$A = \frac{x-y}{xy} = \frac{ \frac{2}{5}- \frac{1}{2} }{ \frac{2}{5} \frac{1}{2} } = \\ \frac{ \frac{4-5}{10}}{ \frac{1}{5} } = \frac{-5}{10} (:5) = -\frac{1}{2}$

Logo, A = $-\frac{1}{2}$