Nico cut out 15 red circles and 10 yellow circles. then he gave away some red circles. how many red circles does nico have left?

If Nico gave away some red circles and you would like to know how many red circles does he have left, you can calculate this using the following step:

Nico has 15 red circles.

n ... the number of red circles that he gave away

15 - n ... the number of circles that Nico still has

The correct result would be 15 - n.

Answer=15-x

Given the data, the following expression can be made, where x is equal to the number of red circles he gave away.

15-x