[tex]\qquad\qquad\huge\underline{{\sf Answer}}♨[/tex]
Let's calculate the slope ~
[tex]\qquad \sf \dashrightarrow \: \dfrac{y_2 - y_1}{x_2 - x_1} [/tex]
[tex]\qquad \sf \dashrightarrow \: \dfrac{3 - 4}{7 - ( - 2)} [/tex]
[tex]\qquad \sf \dashrightarrow \: \dfrac{ - 1}{9} [/tex]
That's the required slope, I hope it helps~