140-(x:7+29)×4=12 720:(5x-12)-56=34

140-(x:7+29)×4=12 (x:7+29)*4=140-12 (x:7+29)*4=128 x:7+29=128:4 x:7+29=32 x:7=32-29 x:7=3 x=3*7 x=21 ===================== 720:(5x-12)-56=34 720:(5x-12)=34+56 720:(5x-12)=90 5x-12=720:90 5x-12=8 5x=8+12 5x=20 x=20:5 x=4 ===============