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Math Score Test Paper of Grade Two in Junior High School
1、4X/(X? -4)=A/(X+2)+B/(X-2)

=[A(X-2)+B(X+2)]/(X+2)(X-2)

=[(A+B)x+2(B-A)]/(X+2)(X-2)

A+B=4

2(B-A)=0

A=2 B=2

b? +A? =2? +2? =8

2、 1/x- 1/y=3

y-x=3xy x-y=-3xy

(2x+3xy-2y)/(x-2xy-y)=[2(x-y)+3xy]/(x-y)-2xy

=(-6xy+3xy)/(-3xy-2xy)

=-3xy/-5xy

=3/5

3、x? +3x+ 1=0

x+3+ 1/x=0

x+ 1/x=-3

x? + 1/X? =(x+ 1/x)? -2

=(-3)? -2

=7

4、 1/(x-5)- 1/(x-6)= 1/(x-8)- 1/(x-9)

[(x-6)-(x-5)]/(x-5)(x-6)=[(x-9)-(x-8)]/(x-8)(x-9)

- 1/(x-5)(x-6)=- 1/(x-8)(x-9)

(x-5)(x-6)=(x-8)(x-9)

x? - 1 1x+30=x? - 17x+72

6x=42

x=7

Inspection: Omission

4(3X- 1)/(2X-2)-(2X)/(3X-3)= 1/2

4(3X- 1)/2(X- 1)-(2X)/3(X- 1)= 1/2

12(3X- 1)-4x = 3(x- 1)

36x- 12-4x=3x-3

29x=9

x=9/29

Inspection: Omission