Which expression can you simplify by combining like terms? Clear Check 6 d 2 +5cd−3dc+8 6d2+5cd-3dc+8 12 c 2 −8 d 2 c+3dc+4 12c2-8d2c+3dc+4 7 d 2 −3 c 2 +6d−c 7d2-3c2+6d-c 16 c 2 +8cd+7c−8d 16c2+8cd+7c-8d