[2×(-1/2)²-3²×(-1/3)³]÷[1-(-1/2)³]
问题描述:
[2×(-1/2)²-3²×(-1/3)³]÷[1-(-1/2)³]
答
[2×(-1/2)²-3²×(-1/3)³]÷[1-(-1/2)³]
=[2×(1/4)-9×(-1/27)]÷[1-(-1/8)]
=(1/2+1/3)÷(1+1/8)
=(5/6)÷(9/8)
=20/27