Which expression is equivalent to (18x + 9k) + (2x + 6k)?

The expression 42 plus 57 shows how much money nate spent at a store .which expression also shows how much money nate spend

Two florida panthers were weighed. one weighs 6x+21 pounds and the two together weigh 14x+11 pounds how much does he other panther weigh alone

Jim had 3,067.48 in his checking account he wrote a check to pay for two airplane tickets. his account now has 1,845.24.