We dissect each statement from the problem above to fully understand it.
the sum of a number and 7 is (x + 7)
3 times this is 3(x + 7)
is means the equal sign here 3(x + 7) =
Two less then 5 times the number is 5x - 2.
Therefore, the answer is B, 3(x + 7) = 5x - 2