Please someone also explain it too.

9514 1404 393

  A  √40

Step-by-step explanation:

The given radical expression can be written as ...

 

The last two versions of this expression tell you two things:

the value under the radical must be a multiple of 4the value under the radical is greater than 16

Only one answer choice meets these requirements:

  √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)