This must be true for all values of \(x\text{.}\) If \(x = 1\text{,}\) then the equation becomes \(1 = -a\) so \(a = -1\text{.}\) When \(x = \frac{1}{2}\) we get \(1 = b/2\) so \(b = 2\text{.}\) This tells us that we can decompose the fraction like this: