3 × 20 - 4 × 10 , 5 × 30 + 10 ÷ 2 , 4 × 30 - 40 × 3 , 50 × 5 + 0 ÷ 5 , ( 75 + 25 ) ÷ 100 , ( 30 + 40 ) × 10 .
3*20-4*10=60-40=20 5*30+10/2=150+5=155 4*30-40*3=120-120=0 50*5+0/5=250+0=250 (75+25)/100=100/100=1 (30+40)*10=70*10=700