题目

Mini Book Excerpts(节选) Biography   When Salinger learned that a car park was to be built on the land, the middle-aged writer was shocked and quickly bought the neighboring area to protect it … The towns-people never forgot the rescue and came to help their most famous neighbor.                                 J.D. Sulinger : A Life by Kenneth Slawenski                                                  (Random House, $27) Mystery (疑案小说) “ You’ re a smart boy. Benny’s death was no accident先仔细看（1）题，再解答（2）题．（1）a为何值时，方程xx-3=2+ax-3会产生增根？解方程两边同时乘以（x-3），得x=2（x-3）+a，①因为x=3是原方程的增根，但却是方程①的根，所以将x=3代入①得：3=2×（3-3）+a，所以a=3．（2）当m为何值时，方程yy-1-m2y2-y=y-1y会产生增根？