Nifal earned 9$ for washing two cars .He recived $1 more for the second car. How much was he paid for washing each car?Which two numbers have a sum of 9$?

Nifal received $ 4 for washing the first car.

Nifal received $ 5 for washing the second car.

4 and 5 have a sum of 9.

Step-by-step explanation:

The problem can be rewritten as follows: Find the sum of two consecutive entire numbers equal to 9. That is:

Then, by eliminating y:

Now, let is clear :

Nifal received $ 4 for washing the first car.

The earning for the second car is: ()

Nifal received $ 5 for washing the second car.

4 and 5 have a sum of 9.