求：

    Years ago, I lived in a building in a large city. The building next door was only a few feet away from mine. There was a woman who lived there, whom I had never met, yet I could see her seated by her window each afternoon, sewing or reading.

    After several months went by, I began to notice that her window was dirty. Everything was unclear through the dirty window. I often said to myself, "I wonder why that woman doesn't wash her window. It really looks terrible."

    One bright morning I decided to clean my flat, including washing the window on the inside.

    Late in the afternoon when I finished the cleaning, I sat down by the window with a cup of coffee for a rest. What a surprise! Across the way, the woman sitting by her window was clearly seen. Her window was clean!

    Then it dawned on me. I was always criticizing(批评) her dirty window, but all the time I was watching hers through my own dirty window.

    That was quite an important lesson for me. How often had I looked at and criticized others through the dirty window of my heart, through my own mistake?

    Since then, whenever I wanted to judge(评判) someone, I asked myself first, "Am I looking at him through my own dirty window?"

    Then I try to clean the window of my own world so that I may see the world around me more clearly and correctly.

股票每天的涨、跌幅均不能超过10%，即当涨了原价的10%后，便不能再涨，叫做涨停；当跌了原价的10%后，便不能再跌，叫做跌停．已知一只股票某天跌停，之后两天时间又涨回到原价．若这两天此股票股价的平均增长率为x，则x满足的方程是（　　）