Answer
$$35$$
Work Step by Step
$$\eqalign{
& \mathop {\lim }\limits_{\left( {x,y} \right) \to \left( {1,3} \right)} \left( {4x{y^2} - x} \right) \cr
& {\text{Using the limit laws }} \cr
& = \mathop {\lim }\limits_{\left( {x,y} \right) \to \left( {1,3} \right)} \left( {4x{y^2}} \right) - \mathop {\lim }\limits_{\left( {x,y} \right) \to \left( {1,3} \right)} \left( x \right) \cr
& {\text{then}}{\text{,}} \cr
& = 4{\left( 1 \right)^2}{\left( 3 \right)^2} - \left( 1 \right) \cr
& {\text{simplifying}} \cr
& = 4\left( 1 \right)\left( 9 \right) - 1 \cr
& = 35 \cr} $$
