Answer:
<h2>The value of the first number is 15</h2>
Step-by-step explanation:
The sum of two number is 40 would be:

The second number is 5 less than twice the first number would be:

Now, we can find the value by solving this system of equations, we will isolate <em>x </em>in the first equation, then we replace it in the second equation:


Then, we replace this value in one equation of find the other variable:

Therefore, the value of the first number is 15 and the second number is 25.