Answer:
5
Explanation:
Ok, so the question is asking us how many hours the plumber worked, which makes it a variable, so let's call it x, times an hourly rate of $50. We already know she paid 200 so let's make that into an equation.
450 = 50x + 200
We need to isolate x, so we have to subtract 200 from each side. The equation should know look like this:
250 = 50x
Now in order to determine x, we need to divide by 50 on both sides.
X = 5
So the plumber worked a total of 5 hours.