Răspuns :
[(624+123:3-a):6]x3+254=554
[(624+123:3-a):6]x3=554-254
[(624+123:3-a):6]x3=300
(624+123:3-a):6=300:3
(624+123:3-a):6=100
624+123:3-a=100x6
624+123:3-a=600
624+41-a=600
665-a=600
a=65
[(624+123:3-a):6]x3=554-254
[(624+123:3-a):6]x3=300
(624+123:3-a):6=300:3
(624+123:3-a):6=100
624+123:3-a=100x6
624+123:3-a=600
624+41-a=600
665-a=600
a=65