Help with geometry

find x and y

$\begin{array}{lrcl} (1) & 8\cdot 9 &=& x\cdot 2x \\\\ (2) & 4\cdot y &=& x\cdot 2x \\\\ (2) = (1) & 4\cdot y &=& 8\cdot 9 \\ & y &=& \frac{8\cdot 9}{4} \\ & y &=& 2\cdot 9 \\ & \mathbf{y} & \mathbf{=} & \mathbf{ 18 } \\\\ (2) & 4\cdot y &=& x\cdot 2x \\ & 4\cdot 18 &=& x\cdot 2x \\ & 72 &=& 2x^2 \\ & 36 &=& x^2 \\ & 6 &=& x \\ & \mathbf{x} & \mathbf{=} & \mathbf{ 6 } \\\\ \end{array}$