1、 2018 4 120 120 1 2 2B 30 10 3 30 1 a a 2 a A. 0 a B. 2 a 0 a C. 2 a 0 a D. 2 a 0 a2. 3 2 5 5 2 - x - - x y , 2xy ( ) A. 15 B.15 C. 15 2 D. 15 23 4. x 2 20 x x m ( ) A. 1 m B. 1 m C. 1 m D. 1 m 5. 1 x 2 x 0 1 3 2 - x x 12 11 xx ( ) A. 1 B.0 C.1 D.2 6. ) 0 ( 0 2 a c bx ax c b a 0 c b a 0 c b - a , (
2、) A.1 0 B.1 1 C. 1 0 D. 7. 1 ( ) 8 1185 580 x ( ) A. 2 580(1+x) =1185 B. 2 1185(1+x) =580 C. 2 580(1-x) =1185 D 2 1185(1-x) =580 9. BC=a AC=b AB=c C D A B A C B CD ( ) A. c a 2B. a b 2C. c abD. c b 210. ABC AB 6cm AC 12cm D A B E C A D 1cm/ E 2cm/ A D E ABC ( ) A. 4.5 B.3 C. 3 4.8 D.4.5 4.8 90 6 3 1
3、8 11 0 5 4 3 c b a c b a c b a12. 5 3 2 x x 11 12 9 2 x 3x 13 Rt ABC B 90 AB 12 CB 8 AD CF O OC 14. x 2 5 1 0 xx 1 x x 15 ABCD , N AB DN CB P AC DN M PN=3 DM _ 16. 1 n n=1 (n=2) (n=3) 8 72 17. 8 (1) 0 1 1 2 1 2 1 2 2 1 18 2 3 2 2 8 1 4 8 a a a a a A B D E C 18. 8 1 0 1 6 3 2 x - x 2 3 3 2 - x - x x
4、19 (8 ) : 2 1 1 3 2 3 3 2 2 a a a a a a a a= 3-2 20. 8 ABCD DEFG AE CG AE CG M CG AD N. 1 CG AE 2 . MN CN DN AN 21. 8 2 1 1 0 xx 2 20 xx x 2 20 xx 12 2, 1 xx x 0 2 20 xx 12 2, 1 xx 12 2, 2 xx 2 1 1 0 xx 22. 9 20 40 . . 1 2 . 1 1200 2 23. 9 x 0 4 4 8 2 m x m - x 2 1 m 2 m 136 m 24. 12 ABCO OA x OC y
5、B 4 3 . M N O B 1 / M OA A N BC C N AC P MP. 1 OA AB 2 3 S t 4 S t . 30 10 3 30 1 5 DADCC 6 10 BADDC 90 6 3 18 11. 3 12. 30 13. 3 20 14. 5 15. 2 16. 1 - n 2 1 8 72 17. 1 2 4 -3 2 a 2 a 2 18. 1 3 6 1 1 x , 3 6 1 2 - x 2 2 1 3 2 1 x x 19 = ) 2 )( 1 ( ) 3 ( a a a a . 3 1 a a - 2 1 a x= 3-2 = 2 a a - 2
6、1 a =1- 3 = 2 1 a a 20. 1 ABCD DEFG AD=CD DE=DG =90 + G= ED+ G E= CDG ADE CDG AE=CG 2 ADE CDG DAE= DCG ANM= CND AMN CDN DN MN CN AN . MN CN DN AN 21. 1 x -1 0 2 x - x 0 1 2 1 x x 2 x -1 0 2 20 xx 1 2 2 1 x - x 1 2 2 1 x - x 22. 1 x 1200 2x 20 x - 40 0 200 30 2 x - x 20 10 2 1 x x 10 x 20 2 y 1250 15
7、 - x -2 800 60x -2x 2x 20 x - 40 y 2 2 x=15 y 15 23. 1 0 16m - 4m - 8 2 2 m=1 m=1 0 4 4x x 2 -2 x x 2 1 2 136 x x 2 2 2 1 8 - 4m x x 2 1 2 2 1 4m x x 136 2 2 1 2 x x - x x 2 1 136 4m 2 - 8 - 4m 2 2 1 9 2 - m m 1 0 m - m - m - 64 64 16 4 8 2 2 -1 m 9 m 1 m 2 1 m 136 24 1 OA=4 AB=3 2 3 S t 2 33 82 s t t 4 2 33 ( 2) 82 st t =2 3 2
