If the electric flux entering and leaving an enclosed surface respectively is ${\phi _1}$ and ${\phi _2},$ the electric charge inside the surface will be
$\left( {{\phi _2} - {\phi _1}} \right){\varepsilon _0}$
$\left( {{\phi _2} + {\phi _1}} \right)/{\varepsilon _0}$
$\left( {{\phi _2} - {\phi _1}} \right)/{\varepsilon _0}$
$\left( {{\phi _1} + {\phi _2}} \right){\varepsilon _0}$
