Răspuns :
{[(a×9 -75):8 +3]:2}×400=1200
[(a×9 -75):8 +3]:2=1200:400
[(a×9 -75):8 +3]:2=3
[(a×9 -75):8 +3]=3×2
(a×9 -75):8 +3=6
(a×9 -75):8=6-3
(a×9 -75):8=3
a×9 -75=3×8
a×9 -75=24
a×9=24+75
a×9=99
a=99:9
a=11
[(a×9 -75):8 +3]:2=1200:400
[(a×9 -75):8 +3]:2=3
[(a×9 -75):8 +3]=3×2
(a×9 -75):8 +3=6
(a×9 -75):8=6-3
(a×9 -75):8=3
a×9 -75=3×8
a×9 -75=24
a×9=24+75
a×9=99
a=99:9
a=11
{[(a×9-75):8]+3}:2×400=1200
{[(a×9-75):8]+3}:2= 1200:400
{[(a×9-75):8]+3}:2= 3
[(a×9-75):8]+3= 3×2
[(a×9-75):8]+3= 6
(a×9-75):8= 3
(a×9-75)=3×8
a×9-75= 24
a×9= 24+75
a×9= 99
a= 99:9
a= 11
{[(a×9-75):8]+3}:2= 1200:400
{[(a×9-75):8]+3}:2= 3
[(a×9-75):8]+3= 3×2
[(a×9-75):8]+3= 6
(a×9-75):8= 3
(a×9-75)=3×8
a×9-75= 24
a×9= 24+75
a×9= 99
a= 99:9
a= 11