79×8/5+7.21×160% 35-15%X=15 23-8/9÷5/6×15/16 2/5X-120×40%=12 急,

79×8/5+7.21×160% =(79+7.21)×1.6=86.21×1.6=137.936;35-15%X=15;0.15x=20;x=2000/15;x=400/3;23-8/9÷5/6×15/16=23-(8/9)×(6/5)×(15/16)=23-2=21;2/5X-120×40%=12 2x/5=12+48;2x/5=60;x=150;