Some answers of Guangzhou senior high school entrance examination: multiple-choice questions D, B, B, A, D, C, C, D, B, A fill in the blanks -9, 154, X = 1, 1 to 2, 124 are correct.

17,- 1/2

18，AE = AF，

Question 19, the original formula = 8x2-16y2-7x2-xy+xy = x2-16y2 = (x-4y) (x+4y).

20 questions, 5 unit of volume, 22 area units.

2 1 problem, (1)12x0.95 =114 yuan.

(2) Let the purchase price be X yuan,168+0.8x.

22 questions, a=50-6-25-3-2= 14.

There are two situations in the second question. One is that there is a person every 6-8 hours, and there is also a person every 8- 10 hours. The probability is 0.6. Another is that there are two people in 8- 10 hours, and the probability is 0.1; The final probability of the two sums is 0.7.

Question 23, K=3, AC=5, b (13/4,0)

Question 24, c= 1, a>o and A are not equal to 1.

25 ellipsis