Answer:
Step-by-step explanation:
hello :
r+b=7... (*)
3.75r+2.75b=22.25.... (**)
use (*) : r = 7 - b
put this value in (**) :
3.75(7 - b)+2.75b = 22.25
26.25 -375b +2.75b = 22.5
-375b +2.75b = 22.5 - 26.25
- b = -3.75
so : b = 3.75
but : r = 7 - b
r = 7 - 3.75
r = 3.25
