题目

I started learning English when I was 6 years old. For 8 years I have learned English in the way everybody else did—by going to English classes. It was useless. I did everything that the teachers told me to do. But I didn’t get any results. I mean, I was always one of the best students in class. However, it took me a long time to read English texts. I made lots of mistakes when writing, and my pronunciation was bad, and I could only speak English very slowly. After my eight years of studying hard, these were the results.In 2003, I went to the best high school in Wroclaw. It was a special s已知反比例函数y=-8x的图象经过点P（a，4），则a= ．