Vector Algebra

Let \(\overrightarrow a = - \widehat i - \widehat j + \widehat k,\overrightarrow a \,.\,\overrightarrow b = 1\) and \(\overrightarrow a \times \overrightarrow b = \widehat i - \widehat j\). Then \(\overrightarrow a - 6\overrightarrow b\) is equal to :