原式=(-1/3)²÷(-1/3)³×(1/3)³÷(3^-2)×(-3)=1/9÷(-1/27)×1/27÷1/3²×(-3)=1/9 ×(-27)×1/27÷1/9 ×(-3)=-3×1/27 ×9×(-3)=-1/9 ×9×(-3)=-1×(-3)=3
