To graph the inequality $16x - 40y > 1600$, first rewrite it as an equation: $16x - 40y = 1600$.
To find the x-intercept, set $y = 0$ and solve for $x$:
$16x - 40(0) = 1600$
$16x = 1600$
$x = 100$
To find the y-intercept, set $x = 0$ and solve for $y$:
$16(0) - 40y = 1600$
$-40y = 1600$
$y = -40$
Plot the x-intercept $(100, 0)$ and the y-intercept $(0, -40)$ on the coordinate plane. Since the inequality is a strict inequality ($>$), draw a dashed line through these points.
Choose a test point not on the line, such as $(0,0)$. Plug the coordinates into the original inequality:
$16(0) - 40(0) > 1600$
$0 > 1600$
Since this statement is false, shade the region that does _not_ contain the test point $(0,0)$.
The nonnegative restrictions $x \ge 0$ and $y \ge 0$ indicate that the solution must be in the first quadrant. So, only shade the portion of the region from Step 4 that is also in the first quadrant.