1、 2017-2018 1 2 I II I 48 II 72 120 120 3 I 2B AB-CD II 4 I II I 12 4 48 1 4 m n 2 m 2 2 n A n 2 m 2 +m B n 2 n m 2C m n 2 m+1 D m n 2 1 m 2 4 x 2 2x 3 A x 1 x+3 B x+1 x 3 C x 1 x 3 D x+1 x+3 3 4 A B C D 4 4 x x a x 2 3 2 1 a A 1 B 0 C 1 D 2 5 4 900kg 1500kg 300kg xkg A x x 1500 300 900 B 300 1500 90
2、0 x xC 300 1500 900 x xD x x 1500 300 900 6 4 5 2 x xy x y 7 A 7 B 14 C 21 D 7 4 4 5 x x 42 4 x x x ( ) A. 0 B. 1 C. 1 2D. 1 8 4 8 7 9 8 8 7 9 6 9 9 A 8 B 8 9 C 9 6 D 9 4 A 2 2 b a b a b a B 1 4 4 4 2 2 y y x y x y y x C 2 2 1 1 2 b a b a b a D x x x x x 4 5 4 5 210 4 A B C D 11 4 A B C D 12 4 A ( )
3、 II 5 4 20 . 13 4 3 2 5 80 90 85 14 4 ABC BC=5 AC=5 ABC CB x ABC y y= x y 15 4 ba a b a b _ _ 16 4 x_ _ 17 4 OA 3 OB 4 x A B O _ 7 52 . 18 6 2 1 1 32 22 x x x x 19 6 6 2 4 ) 3 7 3 ( a a a a 1 a 20 6 50 1 50 2 50 3 600 21 8 ABC C 1 2 1 A B A B 2 ABC 1 2 3 ( 4 ABC 22 8 2500 1000 1.5 5 . 23 9 1 1B1C1 1
4、B1C1 1B1C1 1 2B2C2 1B1C1 2B2C2 2 1B1C1 P 24 9 10 ABC ADE ACB= F BE DF CF. 1 1 D AB E AC DF CF 2 2 1 ADE A 1 3 3 1 ADE A AD=1 AC=22 CF . 2017 2018 1 C m n 2 m 2 2 n m n 2 +m 2 n 2 m n 2 m n 2 m 2 2 n =m n 2 +m 2 n 2 =m n 2 m+1 C 2 B x 2 2x 3= x+1 x 3 B 3 C C 4 A x 2=0 x a 1+3x 6= a+x x 2=0 x=2 1+6 6=
5、 a+2 a=1 A 5 C = 6 D 5 2 x xy x y 7 5 7 7 5 57 2 7 7 2 2 x x x x y x y x y D 7 B x . x 5 4 2x x 4 4 x (x-4) x-5=2x-4 x=-1 x=-1 . 8 C. A 8 B 8 8 9 9 C 7 8 8 8 9 8 6 7 9 9 9 9 D 5 1 2 S 8 8 2 + 7 8 2 + 9 8 2 + 8 8 2 + 8 8 2 = 5 1 2=0.4 2 S = 5 1 7 8 2 + 9 8 2 + 6 8 2 + 9 8 2 + 9 8 2 = 5 1 8=1.6 2 S 2
6、S D C 9 C A B C 2 2 1 1 2 b a b a b a D C 10 C 180 C 11 A A B C D 180 12 D ABC A l20 BAB = CAC =120 AB B= 1 2 - BB C AB = AB B=30 CAB = CAC - C AB =120 -30 =90 D 13 84.5 3 2 5 = 3+2+5 =84.5 84.5 14 x 2 5x+ x x y= 5 x 2 = x 2 5x+ x 2 5x+ 15 -1 = 1 ba ab . 16 1 x -1. -1. 17 36,0 AOB OA=3 OB=4 12 0 3 2
7、4 0 36 0 3 18 x =15 x (x +2) x + x +2=32 -2 x =15- -3 x =15 . 19 = 2 16 4 ( 4)( 4) 2( 3) =2 4 =2 8 3 2( 3) 3 4 a a a a a aa a a a a 1 a -1)+8 =6 1 a 20 1 15 15 2 13 3 7800 1 2 3 1 15 20 15 50 25 26 15+15 15 15 2 50 = 3 21 1 A 2 1 B 4 3 2 3 3 1 5 5 2 4 4 1 2 3 4 1 A 2 1 B 4 3 2 3 3 1 5 5 2 4 4 22 100
8、 x 1500 1500 =5 . x 2500 1000 2500 1000 5 1.5 xx x=100. x=100 100 . 23 1 2 . 1 A2B2C2 A2B2C2 B1 90 A1B1C1 2 CC1 BB1 CC1 BB1 P P 1 2B2C2 2B2C2 B1 1B1C1 2 CC1 BB1 CC1 BB1 P P 24 1 2 3 10 2 1 DF=BF DFE=2 DCF BFE=2 BCF EFD+ EFB=2 DF BF 2 DF BC G DEF GCF DE=CG DF=FG AD=DE AB=BC BD=BG DF=CF DF BF 3 DF BA H DEF HBF DE=BH DF=FH ADH ABC ADE AC=22 AB DH DF DF=BF CF 1 ACB= F BE DF= 1 2 BE CF= 1 2 BE DF=CF ABC ADE BF=DF DBF= BDF DFE= ABE+ BDF DFE=2 DBF CFE=2 CBF EFD+ EFC=2 DBF+2 CBF=2 DF=CF DF CF 2 1 D AC DF BC G ADE= DE BC DEF= GBF EDF= BGF F BE EF=BF DEF GBF DE=GB DF=GF AD=DE AD=GB
