>> y=sym('1/2*(-4*f*d+c^2+c*e*k-2*c*r+c*e*r-r*e*k+r^2-e*r^2+2*f*e*r+2*f*e*k-2*f*r+2*f*c-(r-c-w-p)*(c-r-2*f))*e*(r+k)/(-4*f*d+c^2+2*c*e*k-2*c*r+2*c*e*r+e^2*k^2-2*r*e*k+2*e^2*k*r+r^2-2*e*r^2+e^2*r^2)/f')

y =

(e*(k + r)*(2*c*f - 4*d*f - (2*f - c + r)*(c + p - r + w) - 2*c*r - 2*f*r - e*r^2 + c^2 + r^2 + c*e*k + 2*e*f*k + c*e*r + 2*e*f*r - e*k*r))/(2*f*(c^2 + 2*c*e*k + 2*c*e*r - 2*c*r + e^2*k^2 + 2*e^2*k*r + e^2*r^2 - 2*e*k*r - 2*e*r^2 + r^2 - 4*d*f))

>> collect(y)

ans =

(-(e*(k + r)*(2*f - c + r))/(2*f*(c^2 + 2*c*e*k + 2*c*e*r - 2*c*r + e^2*k^2 + 2*e^2*k*r + e^2*r^2 - 2*e*k*r - 2*e*r^2 + r^2 - 4*d*f)))*w + (e*(k + r)*(2*c*f - 4*d*f - 2*c*r - 2*f*r - e*r^2 - (c + p - r)*(2*f - c + r) + c^2 + r^2 + c*e*k + 2*e*f*k + c*e*r + 2*e*f*r - e*k*r))/(2*f*(c^2 + 2*c*e*k + 2*c*e*r - 2*c*r + e^2*k^2 + 2*e^2*k*r + e^2*r^2 - 2*e*k*r - 2*e*r^2 + r^2 - 4*d*f))