(a) Evaluate : \(2 \div (\frac{64}{125})^{-\frac{2}{3}}\) (b) The lines \(y = 3x + 5\) and \(y = - 4x - 1\) intersect at a point k. Find the coordinates of k.
Explanation
(a) \((\frac{64}{125})^{-\frac{2}{3}} = (\frac{125}{64})^{\frac{2}{3}}\) = \((\frac{5}{4})^{3})^{\frac{2}{3}} \) = \((\frac{5}{4})^{2}\) = \(\frac{25}{16}\) \(\therefore 2 \div (\frac{64}{125})^{-\frac{2}{3}} = 2 \div \frac{25}{16}\) = \(2 \times \frac{16}{25}\) = \(\frac{32}{25}\) (b) \(3x + 5 = - 4x - 1\) \(3x + 4x = - 1 - 5\) \(7x = - 6\) \(x = -\frac{6}{7}\) \(y = 3x + 5\) ( You can use any of the given equations to get y) \(y = 3(-\frac{6}{7}) + 5 = -\frac{18}{7} + \frac{35}{7}\) = \(\frac{17}{7}\) \(k = (x, y) = (-\frac{6}{7}, \frac{17}{7})\)