Respuesta :

distributive property
a(b+c+d)=ab+ac+ad

-7(3e-2f+4)=-7(3e)-7(-2f)-7(4)=-21e+14f-28

now we have

-21e+14f-24+6e-2
group like terms
-21e+6e+14f-24-2
-15e+14f-26