48+56÷7×〇=72;120÷(74-□×16)=12密码是 〇=3,□=4.答案解:48+56÷7×〇=72 48+56÷7×x=72 48+8x=72 48+8x-48=72-48 8x=24 8x÷8=24÷8 x=3120÷(74-□×16)=12120÷(74-y×16)=12 120÷12=74-16y 10=74-16y 10+16y=74-16y+16y 10...