If 52s + 64b = 4,892 and if s + b = 83 what are the values of s and b?

(1) 52s + 64b = 4,892

(2) s + b = 83  |subtract b from both sides
     s = 83 - b

subtitute (2) to (1):

52(83 - b) + 64b = 4,892
4,316 - 52b + 64b = 4,892
12b + 4,316 = 4,892    |subtract 4,316 from both sides
12b = 576    |divide both sides by 12
b = 48

subtitute the value of b to (2)

s = 83 - 48
s = 35

s = 35 and b= 48.

It is 7 because it is the absolute value