if a+3b=13 and a+b=5, the value of b is

Question

a 4.5
b 7
c 1
d 4

Answer 1

use substitution
change the second to a = 5-b
now sub that back into the first
let me know what you got for b.

Answer 2

i got my answer as 1 (C).is that correct !!!

Answer 3

no
from the second: a = 5-b

that into the first:
a+3b=13
(5-b) + 3b = 13
2b = 13-5
2b=8
b = 4