Question 1002172


{{{5/(z-4)(z+2)}}}

Rational expressions are undefined when the denominator is equal to {{{0}}}. Since the denominator is equal to {{{(z-4)(z+2)}}}, make it equal to {{{0}}} and solve for {{{z}}}.

{{{(z-4)(z+2)=0}}}

if {{{(z-4)=0}}}=>{{{z=4}}}
if {{{(z+2)=0}}}=>{{{z=-2}}}

the rational expression is defined for all real numbers excluding {{{z=4}}} and {{{z=-2}}}