Выражения: а) 6/m^3+8+1\2m+m^2 б) 12\x^2+12x+36+12\x^2-36-1\x-6 в) 2x\x-1+3x+1\1-x^2-3\x+1

6/(m^3+8)+1/m(m+2)=(6m+m^2+4-2m)/m(m^3+8)=(m+2)^2/m(m^3+8)
12/(x+6)^2+12/(x^2-36)-1/(x-6)=(12x-12*6+12x+12*6-x^2-36-12x)/(x-6)(x+6)^2=

=(x-6)^2/(6-x)(x+6)^2=(6-x)/(x+6)^2

2x/(x-1)+(3x+1)/(1-x^2)-3/(x+1)=(-2x^2-2x+3x+1-3x+3)/(1-x^2)=

=(-2x^2-2x+4)/(1-x^2)=-2(x^2+x-2)/(1-x^2)=2(1-x)(x+2)/(1-x^2)=2(x+2)/(x+1)