Make x the subject of the formula where x is positive
b= x -6 / x + 2

Answer:
[tex]b = \frac{x - 6}{x + 2} \\ b(x + 2) = x - 6 \\ bx + 2b = x - 6 \\ bx - x = - 6 - 2b \\ x(b - 1) = - 2(3 + b) \\ x = \frac{ - 2(3 + b)}{b - 1} [/tex]