=[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