计算:加、减、乘、除138+17=230-199=6-1.9-2.1=8.9+3.8+1.1=0.4+0.06=1.6-0.06=0.65+4.35=18.2+0.28=3.5×0.2=1.25×80=0.26×10=2.4×5=13×6=17×3=14×3=1.9×3=8181÷81=648÷6=3636÷6=4.2÷0.07=1.4÷7=0.96÷0.3=3.6÷1.2=0.5÷0.25=-×0=2-2÷9=1÷×=10÷×10=×=15÷=×=0.25×1×4=+=4+5=91×=-(+)=0.23+177%=8×12.5%=3+20%=200×()﹪=840×25%==0÷==0÷25×8-1=+×0=1-0.5=10-1=32:16=0.125:0.3=():=():=():=():=25×4=125×8=200×5=24×5=0.1=0.2=0.3=0.4=0.5=6=7=8=9=10=л=2л=3л=4л=5л=6л=7л=8л=9л=10л=1л=2л=3л=4л=5л=6л=7л=8л=9л=10л=1%=2%=3%=4%=5%=6%=二、能简算的要简算0.66+7.5+0.34+2.58×+8×+8×2.5×8-350÷70÷[(+)×6]16.5-7.3-1.4-1.32.9+385÷35×4.336×()×-0.2×11+0.75×11168.1÷(4.3×2-0.4)5.89+3.6×0.2﹢0.2836×()()×12[3-(+)]×[1-()]÷563×999125×32101×8546×57.5-4.25-15.75÷5+××101-三、求未知数的值。+16=30:0.5=3:x==3.4:=:4=+4=10:=:8=5.5x–3x=1.75=15÷X=2X–=:=:15=1.75:42=:105.5x–3x=1.75(1–)X=5.5-50%=6.4