$$\mbox{This\;is\;just\;an\;example\;because\;there\;are\;many\;solutions\;to\;this\;problem,\;so\;I\;just\;hope\;it\;helps!}$$
$$\mbox{First,\;make\;an\;expression.}$$
$$\left({\mathtt{x}}{\mathtt{\,\small\textbf+\,}}{\mathtt{y}}{\mathtt{\,\times\,}}{\mathtt{x}}\right)$$
$$\mbox{Now,\;substitute\;x\;and\;y.}$$
$$\left({\mathtt{x}}{\mathtt{\,\small\textbf+\,}}{\mathtt{y}}{\mathtt{\,\times\,}}{\mathtt{x}}\right) = \left({\mathtt{14}}{\mathtt{\,\small\textbf+\,}}\left(-{\mathtt{2}}\right){\mathtt{\,\times\,}}{\mathtt{14}}\right)$$
$$\mbox{Now,\;do\;the\;work\;inside\;the\;parentheses.}$$
$$\left({\mathtt{14}}{\mathtt{\,-\,}}\left({\mathtt{2}}\right)\right) = {\mathtt{12}}$$
$$\mbox{Now\;multiply.}$$
$${\mathtt{12}}{\mathtt{\,\times\,}}{\mathtt{14}} = {\mathtt{168}}$$
$$\mbox{And\;now\;you\;have\;your\;answer.}$$
$${\mathtt{Final}}$$$${\mathtt{Answer}}$$:$${\mathtt{168}}$$
$$\mbox{Hope\;it\;helps!}$$
.