a, $x^{}$ x $6^{}$ + $167^{}$ = $191^{}$
$x^{}$ x $6^{}$ = $191^{}$ - $167^{}$
$x^{}$ x $6^{}$ = $24^{}$
$x^{}$ = $24^{}$ : $6^{}$
$x^{}$ = $4^{}$
b, $x^{}$ : $8^{}$ : $6^{}$ = $12^{}$
$x^{}$ : $8^{}$ = $12^{}$ x $6^{}$
$x^{}$ : $8^{}$ = $72^{}$
$x^{}$ = $72^{}$ x $8^{}$
$x^{}$ = $576^{}$
c, $682^{}$ + $x^{}$ : $5^{}$ = $718^{}$
$x^{}$ : $5^{}$ = $718^{}$ - $682^{}$
$x^{}$ : $5^{}$ = $36^{}$
$x^{}$ = $36^{}$ x $5^{}$
$x^{}$ = $180^{}$
d, $x^{}$ : $8^{}$ - $16^{}$ = $37^{}$
$x^{}$ : $8^{}$ = $37^{}$ + $16^{}$
$x^{}$ : $8^{}$ = $53^{}$
$x^{}$ = $53^{}$ x $8^{}$
$x^{}$ = $424^{}$
@Saphire
