1. You can add 7 units to both sides of the scale so it becomes a balance between x on the left and 21 on the right. x ___ 21
1A) The only number from the set that will keep the balance is x ∈ {21} 1B) The number on the right (21) will be more than x for x ∈ {0, 1, 7, 14} 1C) The number on the right (21) will be less than x for x ∈ {28, 30}
