Question

R+b=7
3.75r+2.75b=22.25

Answer 1

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