1、 2017-2018 2 20 1. 2 +3.5 0 3 2 0.7 11 A l B 2 C 3 D 4 2 3 ) 2 ( 2 3 2 A 21 B 35 C 35 D 29 3 273 0 C , 0 K, 272 0 C 1 K, 100 0 C A 173 K B 173 K C 373 K D 373 K 4 (A) 0 9 ) 3 ( 3 (B) 36 ) 9 ( ) 4 ( (C) 1 3 2 2 3 (D) 4 ) 2 ( 2 3 5. 2 3 y x 0 2 1 x x 2 1 2 1 x 0 3 2 2 x x A 1 B 2 C 3 D 4 6. a 7b 2 4 2
2、a 14b ( ) A 0 B 2 C 4 D 8 7 3x 2 -2xy-y 2 -5x 2 +xy-2y 2 ( ) A.-2x 2 -xy-3y 2 B.2x 2 +xy+3y 2C.-8x 2 +3xy-y 2D.8x 2 -3xy+y 28 ( ) 9 ( ) A 4x 3 y 2xy 3 B 4yx 7xy C 9xy 3x 2 Dab bc 10 a b a-b + a+b a 0 b A. 2a B. -2a C. 0 D.2b 3 30 11. 6000 6000 12. - 3 2 x 3 yz -2ax+7abx 4 -4ax 3 y 2 -5 13. 1 2 a a 2
3、 1 a 14. 3 1 _ 3 2 1 _. 3 9 _ 15. 1 5 x a 1 y 3x 2 y b 3 a 3b _. 16 0 6 3 1 2 a x a x 17. x = -3 x a = 6 , a = 18 3a+2b +(b-3) 2 =0, a b = .19 48 6 x _ . 20. 2 5 10 17 26 . n _ 3 15 l 5 1 ) 2 ( 4 2 3 2 ) 4 1 1 ( ) 2 ( 32 ) 5 3 ( ) 5 ( 2 3 3 4 29 x 4 3 2 5( 2) xx 5 1 4 2 3 1 2 y y (12 ) 4 8 (1)(3a 2
4、ab 7) (5ab 4a 2 7) a 2 b 1 3 (2)3(ab 5b 2 2a 2 ) (7ab 16a 2 25b 2 ) |a 1| (b 1) 2 0. 5 25 1. 1 A +15 -2 +5 -1 +10 -3 -2 +12 +4 -5 +6 2 A -17 +9 -2 +8 +6 +9 -5 -1 +4 -7 -8 1 1 2 A A 6 2 a 2. 3 3 12.5 3 2.4 X X3 (1) X (2) 10 (5 ) 3. 20 1.5 35 1323 5 4 2.8 3 24km/h, 1 2 6 5. 6 240 5 BDDDA DDBBB 11.6 12.-2/3,5, 13.-1/2 14.-3,-5/3,-12 15.-3 16 .1,2 17.-9 18.-8 19.1/2X+6 ,28,20 20.n2+1 1 -16/5,(2)85(3)33(4)-1(5)-2/5 (1)7a2-6ab,24 (2)-4ab+10b2-10a2,4 1. 1 4km,(2)65a,76a 2.2.4X+5.3 29.3 3.1080 4.2016 5.4
