(-2)平方-丨-7丨+3-2*(-1/2) =4-7+3+1=13/2*[3*(-2/3)平方-1]-1/3*(-2)立方=3/2×﹙3×4／9-1)-1/3×(-8)=3/2×1/3+8/3=1/2+8/3=19/6
