Respuesta :

Step-by-step explanation:

2.3r - 7 + 6 = 21

2.3r - 1 = 21

2.3r = 22

r = 22/2.3

r = 9.6

2.3(4.23) - y + 6 = 21

9.73 - y + 6 = 21

15.73 - y = 21

-y = 5.27

y = -5.27