To solve the equation 210-5x=200, we need to isolate the variable x.

First, let's subtract 210 from both sides of the equation:

210 - 210 - 5x = 200 - 210

This simplifies to:

-5x = -10

Next, divide both sides of the equation by -5:

-5x / -5 = -10 / -5

This simplifies to:

x = 2

Therefore, the solution to the equation 210-5x=200 is x = 2.