1、 2018 2017 2018 (2017.11) 1-5. ADCAA. 6-10.DCCAB. 11-12.DB 13. 14. -2 15. ( ) 16. 17. 5 18. 19. 1 x-3 (x-3+2x)=0 2 x-3=0 x-3+2x =0 3 x1=3,x2=1 4 (2) a=3 b=-6 c=1 b2-4ac=(-6)2-4 3 1=24 0 1 3 4 20 . 3 5 . 8 21 . O AB AE=CE, OE ABC OE BC. 3 BF AC BCEF . 5 6 BCEF . 8 22. 1 4 2 6 A 2 A 8 23. 1 4 6 60-4=5
2、6 7 56 8 24. 1 DE=OC DE AC OCED AC BD COD=90 OCED OE=CD 4 2 ABCD ABC=60 AC=AB=4 OCED CE=OD= = ACE AE= = 8 25. AC=8 BC=6 AB=10 CD AB S = CD= = =4.8 CD 4.8 3 2 DP=t CQ=t CP=4.8 t PQ CD a QCP ABC t=3 4 PQ AC b PCQ ABC t= t 3 6 3 CQ=CP 1 t=4.8 t t=2.4 7 PQ=PC 2 PQ=PC PH QC QH=CH= QC= CHP BCA t= 9 QC=QP Q QE CP E 3 t= 11 t 2.4 CPQ 12
