isolating a common factor from a sum of terms



> -c5*v5*D-8*c2*v4*D-c5*h*D+u2*v2*v6+u3*v6-6*u4*v3+4*u2*v3-4*c2*u3*v2+4*u4-2*c2*u1+4*u1+4*c2*c4

> Is there a straightforward way to factor out the common factor "2*c2" from the four terms in which it appears?

Try facsum

(%i108) facsum(%,c2);
(%o108) -2*c2*(4*v4*D+2*u3*v2+u1-2*c4)-c5*v5*D-c5*h*D+u2*v2*v6+u3*v6-6*u4*v3+4*u2*v3+4*u4+4*u1

--Barton