Question 993190
The complement of an angle is what, when added to it, equals {{{90}}}°. 

{{{alpha+beta=90}}}°

if {{{alpha=(4x -12)}}}°, then its complement is {{{beta=90-(4x -12)}}}°

=>{{{beta=90-4x +12}}}°

=>{{{beta=(102-4x)}}}°


The supplement of an angle is what, when added to it, equals {{{180}}}°. 

{{{alpha+beta=180}}}°

if {{{alpha=(4x -12)}}}°, then its complement is {{{beta=180-(4x -12)}}}°

=>{{{beta=180-4x +12}}}°

=>{{{beta=(192-4x)}}}°


so, if given angle {{{(4x -12)}}}°, its complement is {{{(102-4x)}}}° and its supplement is {{{(192-4x)}}}°