To solve for x, we need to get x by itself on one side of the equation. To do this, we can start by subtracting 1.4x from both sides of the equation. This gives us:
3 1/2 - 1.4x ≥ 0
Next, we can simplify the left side of the equation to get:
7/2 - 7/5x ≥ 0
Now we can divide both sides of the equation by -7/5 to get:
-5/2x ≤ -7/2
Finally, we can multiply both sides of the equation by -2/5 to get:
x ≥ 4 9/10
Therefore, the solution is x ≥ 4 9/10, which corresponds to answer choice C.