大家帮我出20道有理数的运算题,

1、48÷[(-2)^3-(-4)] =48÷(-8+4) =48÷(-4) =-12 2、(-1)^3×(-5)÷[(-3)^2+2×(-5)] =(-1)^3×(-5)÷(9-10) =(-1)×(-5)÷(-1) =-5 3、(-2/9)+(-7/9)-(-2) =-1+2 =1 4、4.6-(-3/4+1.6-4)-3/4 =4.6-(-3.15)-0.75 =7.75-0.75 =7 5、(1/2-3+5/6-7/12)÷(-1/36) =(-27/12)÷(-1/36) =81 6、[3/4+(-1/2)-(-7/8)]÷(-7/8) =(9/8)÷(-7/8) =-9/7 7、-3×(-1/3)^3-(1/3)^2÷(-2/3)^2 =(-3)×(-1/27)-(1/9)÷(4/9) =1/9-1/4 =-5/36 8、[-1/3×(-1/2)+(-1/9)÷2/3]÷(-2)^3 =(1/6-1/6)÷(-8) =0÷(-8) =0 9、[(-3)^2-2^2-(-5)^2]×(5/6÷4/9)×(-2)^4 =(9-4-25)×(15/8)×16 =(-20)×(15/8)×16 =-600 10、4又1/2×[-3^2×(-1/3)^2-0.8]÷(-5又1/4) =(9/2)×[-9×(1/9)-0.8]÷(-21/4) =(9/2)×(-1.8)÷(-21/4) =(-81/10)÷(-21/4) =54/35 11、2×92.35^2+83.96^3 =2×8528.5225+7049.2816 =17057.045+7049.2816 =24106.3266 12、[2/3÷(-4)-1/4×(-0.4)]÷(1/3)^2-(-2) =(-1/6+0.1)÷(1/9)+2 =(-1/15)÷(1/9)+2 =(-3/5)+2 =1.4