Does 2x + 15 mean you have to add or multiply. I know there’s an addition sign, but the 2x makes me feel like I have multiply and I’m currently confused.

C. expression because any expression or equation may contain more than one variable

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)