Răspuns :
324×27-40:5+(a×7-12)=8784
8748-8+(a×7-12)=8784
8740+(a×7-12)=8784
a×7-12=8784-8740
a×7-12=44
a×7=44+12
a×7=56
a=56:7
a=8
8748-8+(a×7-12)=8784
8740+(a×7-12)=8784
a×7-12=8784-8740
a×7-12=44
a×7=44+12
a×7=56
a=56:7
a=8
8784-8+7a-12=8784
8740-12+7a=8784
8728+7a=8784
7a=8784-8728
7a=56
a=56:7
a=8
8740-12+7a=8784
8728+7a=8784
7a=8784-8728
7a=56
a=56:7
a=8