If a = 1, b = 3, solve for x in the equation (frac{a}{a – x}) = (frac{b}{x – b})

A.
(frac{4}{3}) 
B.
(frac{2}{3}) 
C.
(frac{3}{2}) 
D.
(frac{3}{4})
Correct Answer: Option C
Explanation
(frac{a}{a – x}) = (frac{b}{x – b})
(frac{1}{1 – x}) = (frac{3}{x – 3})
∴ 3(1 – x) = x – 3
3 – 3x = x – 3
Rearrange 6 = 4x; x = (frac {6}{4})
= (frac{3}{2})