Question

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

Answer 1

Answer:

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:

$x + y = 9$

$y = x+1$

Then, by eliminating y:

$x + (x+1) = 9$

$2\cdot x + 1 = 9$

Now, let is clear $x$:

$2\cdot x = 8$

$x = 4$

Nifal received $ 4 for washing the first car.

The earning for the second car is: ($x = 4$)

$y = x +1$

$y = 4 + 1$

$y = 5$

Nifal received $ 5 for washing the second car.

4 and 5 have a sum of 9.