rut gon bt a)x^4+4x^2+8/2x^3+2 .x/12x^2+1 .3x^3+3/x^4+4x^2+8 b)x^6+2x^3+3/x^3-1 .3x/x+1 .x^2+x+1/x^6+2x^3+3 c)x^3+2x^2-x-2/3x+15(1/x-1-2/x+1+1/x+2)  d)x-1/x-2 .(x-2)^2/x-3 .(x-1)(x-3)/x^2-4  e)x-1/x^3+1 .(x^2-x+1) .x+1/x-1  g) y-1/2y .(y^2+y+1+y^3/y-1) giup mik voi a