Original formula == >3=(Ax+B)*(x+2)+C(x+ 1) Both sides of the equation are multiplied by (x+ 1)(x+2).
= = = & gt3=Ax^2+2Ax+Bx+2B+Cx+C
= = = & gt3=Ax^2+(2A+B+C)x+(2B+C)
The above formula applies to any x≦- 1 and x≦-2, so:
A=0
2A+B+C=0
2B+C=3
Simultaneous solution: A=0, B=3, C=-3.