What two numbers have a sum of 22 their difference is 4?

Answer 1

Let's say the numbers are x and y.

Then:

• x + y = 22, since you said the sum of them is 22
• x - y = 4, since you said the difference between them is 4

We can compile this into a system of equations:

1) x + y = 22

2) x - y = 4

Using the substitution method on equation no. 2 we can write no. 1 as:

(y + 4) + y = 22 <=> 2y + 4 = 22 <=> 2y = 18 <=> y = 9

Plugging the value into no. 2, we get:

x - 9 = 4 <=> x = 4 + 9 = 13

Doublechecking:

13 + 9 = 22, true

13 - 9 = 4, true

Therefore the two numbers are 9 and 13!