Question 889960
Do you want the number or the numbers?

I assume you need to find the two numbers.

Let x and y be the two numbers.

x + y = 107
x - y = 17

We have a system of linear equations in two variables.

Notice right away that both y letters cancel out. See it?

We are left with 2x = 124.

Solve for x.

2x = 124

x = 124/2

x = 62

We found x to be 62.

Now plug x = 62 into EITHER equation above to find y.

I will use x + y = 107 but you can use the other equation if you'd like.

So, x = 62.

Then 62 + y = 107

Solve for y.

y = 107 - 62

y = 45

The two missing numbers are 45 and 62.