describe how the following expressions are obtained: 7xy+5,x2y,4x2-5x
 

Dear Student,

$$\begin{gathered} \left(1\right) 7\mathrm{xy}+5 \\ \mathrm{Multiply} \mathrm{the} \mathrm{variable} \mathrm{x} \mathrm{with} \mathrm{other} \mathrm{variable} \mathrm{y}, \mathrm{we} \mathrm{get} \mathrm{xy}. \mathrm{Again} \mathrm{multiply} \mathrm{xy} \mathrm{with} 7 \mathrm{then} \mathrm{we} \mathrm{get} 7\mathrm{xy} \\ \mathrm{and} \mathrm{add} 5 \mathrm{to} 7\mathrm{xy} \mathrm{to} \mathrm{get} \mathrm{the} \mathrm{expression} 7\mathrm{xy}+5. \\ \left(2\right) {\mathrm{x}}^2\mathrm{y} \\ \mathrm{Multiply} \mathrm{variable} \mathrm{y} \mathrm{with} \mathrm{square} \mathrm{of} \mathrm{other} \mathrm{variable} \mathrm{x}. \\ \left(3\right) \\ 4{\mathrm{x}}^2-5\mathrm{x} \\ \mathrm{Multiply} \mathrm{square} \mathrm{of} \mathrm{variable} \mathrm{x} \mathrm{with} 4 \mathrm{and} \mathrm{then} \mathrm{subtract} \mathrm{multiple} \mathrm{of} 5 \mathrm{and} \mathrm{x}. \end{gathered}$$

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