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=128x:7+29=128:4x:7+29=32x:7=32-29x:7=3x=3*7x=21===================== 720:(5x-12)-56=34 720:(5x-12)=34+56720:(5x-12)=905x-12=720:905x-12=85x=8+125x=20x=20:5x=4===============