18.5 discount

270% ,30%,240

39

4 120÷80%= 150, 150×90%= 135

5210 ÷ 70% = 300,300-210 = 90 (yuan)

665438+500,000 ÷ 3 million =50%

7 15%, 4000× (1+15%) = 4600 (kg)

86000+6000×2.89%×2=6346.8 (yuan)

9(2800-2000)×5%=40 (yuan)

Thanks for adoption