Relax

Respuesta :

Answer:

7

Step-by-step explanation:

x

+

y

=

21

x

y

=

7

y

=

21

x

x

(

21

x

)

=

7

x

21

+

x

=

7

2

x

=

28

x

=

14

14

+

y

=

21

y

=

7