Answer
slope = $\dfrac{-a}{b}$
The line through the points falls from left to right.
Work Step by Step
RECALL:
(i) The slope, $m$, of the line that passes through the points $(x_1, y_1)$ and $(x_2, y_2)$ is given by the formula:
$m=\dfrac{y_2-y_1}{x_2-x_1}$
(ii) A line whose slope is positive rises from left to right.
(iii) A line whose slope is negative falls from left to right.
(iv) A line horizontal line has a slope of zero.
(v) A vertical line has an undefined slope.
Use the formula in (i) above to find the slope of the line that passes through the points $(0, a)$ and $(b, 0)$ to obtain:
$m=\dfrac{0-a}{b-0}=\dfrac{-a}{b}$
Since both $a$ and $b$ are positive, then $\dfrac{-a}{b}$ must be negative.
Thus, the line that passes through the two given points falls from left to right.
