x^2+x+1=(x+1/2)^2+3/4, use subst: (sqrt(3)/2)*t=x+1/2, do you see why?

the second one: for the numerator: -(4x+1)=-(4x+2-1)=-2(2x+1)+1 then separate the fractions, for the first fraction use subst. u=x^2+x+1, do u see why? for the second fracction, proceed using the first hint i gave initially.