Răspuns :
{2x[30+(4xa-12)+4]}=6364:37
{2x[30+(4xa-12]}=172
[30+(4xa-12)+4]=172:2
[30+(4xa-12)+4]=86
30+(4xa-12)=86-4
30+(4xa-12)=82
(4xa-12)=82-30
(4xa-12)=52
4xa=52+12
4xa=64
a=64:4
a=16
{2x[30+(4xa-12]}=172
[30+(4xa-12)+4]=172:2
[30+(4xa-12)+4]=86
30+(4xa-12)=86-4
30+(4xa-12)=82
(4xa-12)=82-30
(4xa-12)=52
4xa=52+12
4xa=64
a=64:4
a=16