#### Answer

Option $D$

#### Work Step by Step

With $x$=second number, then
"six times a second number" = $6x$
"three less than six times a second number" = first number = $6x-3$
The sum of the two numbers is 46 so
$(6x-3) + x = 46$
Therefore, the equation needed to solve the given problem is the one in Option $D$.