Answer:
The three numbers from the largest to the smallest are:
43, 20 and -7
Step-by-step explanation:
Let the three numbers be: x, y and z.
Since their sum is 56, we have:

Suppose z is the largest, and x, the smallest. As their difference is 50, we have:

Lastly, given that the sum of the two smaller numbers is 13, we have:

We want to find the values of x, y and z.
Using the last equation in the first equation, we can replace (x+y) by 13 to have:

Subtracting 13 from both sides, we have:

Now, using z = 43 in the second equation, we have:

Subtracting 43 from both sides

Divide both sides by -1

Finally, using x = -7 in the third equation, we have:

Add 7 to both sides

Therefore, the three numbers from the largest to the smallest are:
43, 20 and -7