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