The questions are 12 & & ' 13 .

An equation has a left side a right side and a equal sighn separating the sides and expression dosenr have any sides.

An equation has an 'equals' sign for example, 7+5=12 however an expression doesn't for example, X+2

Hope this helped

38+105= 143, 39+104=143, and you will find then adding the numbers on opposite sides, moving inwards yields the answer 138 every time. because of this, you’re going to multiply 138 times the number of pairs, which is 34. therefore, 34*138= 4692(i’m sorry if it’s the wrong numbers, but it’s the right concept)