Steps:
(Let x = greater number and y = lesser number)
So this question is asking us for a system of equations. Using the info they provide, we can form these two equations:

So for this, we will be using the substitution method. Since we know that x = y + 7, substitute x with (y + 7) in the second equation as such:

From here we can solve for y. Firstly, distribute 3 so that it multiplies with y and 7:

Next, subtract 3y on both sides of the equation:

Lastly, subtract 5 on both sides of the equation:

Now that we know the value of y, we can substitute it into either equation to solve for x:

Answer:
In short, 16 is the lesser number and 23 is the greater number.