$\text{The slope of the line joining the points } (x_1,y_1) \text{ and } (x_2,y_2) \text{ is given by } m=\dfrac{y_2-y_1}{x_2-x_1}$.So, the slope of the line joining the points \(\left(-3,10\right)\) and \(\left(6,9\right)\) is \(\dfrac{\left(9\right)-\left(10\right)}{\left(6\right)-\left(-3\right)}\) = \(\dfrac{9-10}{6+3}\) = \(\dfrac{-1}{9}\) = \(-\dfrac{1}{9}\)The slope is negative, so the line is falling from left to right.