1÷[(-2)²×0.5²-(-2.24)÷(-2)³]-1又7/18
=1÷[4×0.25-2.24÷8]-25/18
=1÷[1-0.28]-25/18
=1÷0.72-25/18
=1÷18/25-25/18
=25/18-25/18
=0