(x-1)/(x^2+3x+2)+6/(2+x-x^2)-(10-x)/(4-x^2)

　　=(x-1)/(x+1)(x+2)-6/(x+1)(x-2)-(x-10)/(x+2)(x-2)

　　=[(x-1)(x-2)-6(x+2)-(x-10)(x+1)]/(x+1)(x+2)(x-2)

　　=(x^2-3x+2-6x-12-x^2+9x+10)/(x+1)(x+2)(x-2)

　　=0/(x+1)(x+2)(x-2)

　　=0

　　（x的2方-x-6分之x的2方-4+x-3分之x+2)除以x-3分之x+1=

　　=[(x+2)(x-2)/(x-3)(x+2)+(x+2)/(x-3)]/[(x+1)/(x-3)]

　　=[(x-2)/(x-3)+(x+2)/(x-3)]*[(x-3)/(x+1)]

　　=[(x-2+x+2)/(x-3)][(x-3)/(x+1)]

　　=2x/(x+1)

　　x-y分之x乘以x+y分之y的2方-x的4方-y的4方分之x的4方y除以x的2方+y的2方分之x的2方

　　={[x/(x-y)]*y^2/(x+y)-x^4y/(x^4-y^4)}/(x^2+y^2)

　　=[xy^2/(x^2-y^2)-x^4y/(x^4-y^4)]/(x^2+y^2)

　　=(x^3y^2+xy^4-x^4y)/(x^4-y^4)(x^2+y^2)