$$\left. \begin{array} { l } { 3 a + 4 b = a b } \\ { 7 b + 50 a = 18 a b } \end{array} \right.$$
$a=0\text{, }b=0$
$a=-\frac{179}{4}=-44.75\text{, }b=\frac{179}{65}\approx 2.753846154$
