3 3-1

1.abb0abab abab

2.ab ab

b

(1) 1244 (2) 2.82.1 (3) (1)12 44= (2)2.8 2.1= (3)

3.

11040=7040=74

1.(1)a3b5ab= (2)(1)(2a2-7b2)8ab3a=5b= rab=(2a2-7b2)8ab=[2(5r)2-7(3r)2]8(5r)(3r) =[50r2-63r2]120r2= -13r2120r2(1) 53 (2)

2. xy= 2x7y= 3x+3y=12x-4y7y=9xxy= 792x7y= 27r79r= 29: (1) 7 : 9 (2) 2 : 9

3.206 154123 92 ===== = = = :

4.21 2r r

: = = 8 : 9: 8 : 9

5.534 7 5 = 3= t1= t/51= t/37 = 4= d1 = d/71= d/4=== 20 : 21: 20 : 21

6. 237. 2 = a2x3x2a=36xa=18x=: 6

1. (A)2715 (B)10ab5ab (ab0) (C) (D)(2.5)(1500) 2715 = 271510ab5ab (ab0) = 105 = 3015 = 43 = 2015 (2.5)(1500) = 2.51.5 = 2515 : C

2.a=3bc= 3a9c= (A)21 (B)31 (C)13 (D) 3a9c = 3(3b)9(b/2)= 9b9b/2= 18b9b= 21: A

3.200 31300400 (A)65 (B)70 (C)75 (D)80 3rr3r+r=200r=50=: A

4.6010020 (A)49 (B)50 (C)66 (D)67 60100 = 60 () = 60 (100+20) = 50 : B

5.25 40 (A)45 (B)50 (C)60 (D)75 (40-25) 25 = 60 : C

6.75918 (A)1220 (B)53 (C)306 (D) = 918 75= 1224 = 7525= 31= 251224 = 306: C

7.35 (2)(3) (A)25 (B)52 (C)910 (D)109 1 a1 b 3a=5b(2)(3) = 2a3b = 2(5b/3)3b= 10b9b = 109 : D

8.35 (A)35 (B)53 (C)65 (D)310 a 3x5x== 5ax3ax = 53: B

9.68 (A)=34 (B)=34 (C)=916 (D) = 68 = 34 = 6 48 4 = 34 = 6282 = 3664 = 916: D

10.a0b0abmban (A)m+n=1 (B)m-n=1 (C)mn=1 (D)mn=1 mn=1 : C

11.12 a2a= 6a26(2a)2 = 6a224a2 = 14= a3(2a)3 = a38a3 = 18: (1) 14 (2) 18

12.12004001600 600 4008006001000 = (400+600) (800+1000) = 10001800 = 59 : 59

13.xy03x-y=7x+5yxy= 3x-y=7x+5y3x-7x=5y+y-4x=6y xy = 6(-4) = 3(-2): 3(-2)

14. 6048 v2a v=40: 40 60aa/60vaa/v2a/48

15.6408 = 40 6= 24== 7.5 : 7.5

16.74 = 1/71/4 = 47 : 47

17.233 4a =: 8a/92 = 3= d1= d/21= d/33 = 4= t1 = t/31= t/4axax = 9 8x = 8a/9

18.rR

rR

=

rR