# Thread: Find two numbers where difference is 20 & the sum is -4

1. ## Find two numbers where difference is 20 & the sum is -4

Find 2 numbers such that the difference between them is 20 and their sum is -4.

Is there a systematic way or method to solve this besides just guessing integers?

(p.s. No algebra allowed, this is a pre-algebra questions)

2. The only systematic way to solve this that I know of is to use linear algebra:

x - y = 20
x + y = -4.

Turn the crank.

3. Hi

A clue, one of the numbers you want is 8, can you work out the other number?

4. Divide the difference equally between the two numbers.

Half of 20 is 10, half of -4 is -2. Add and subtract -2 to and from 10.

Think about what the signs should be.

(As Ackbeet implies "systematic" pretty much means algebra!)

5. Originally Posted by Kick
Find 2 numbers such that the difference between them is 20 and their sum is -4.

Is there a systematic way or method to solve this besides just guessing integers?

(p.s. No algebra allowed, this is a pre-algebra questions)
Two simultaneous equations is a systematic way towards solving that type of problem.