Which ideas did you include in your explanation? Check all that apply. The second number is 40. The first number of each ratio is multiplied by 4 to get the second number. 5 is multiplied by 2 to get 10. So, multiply 20 by 2 to get 40.

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)