In the xy-plane above, o is the center of the circle, and the measure of

3x = 50 - 10y

Step-by-step explanation:

Here, x represents the number of 3 lb weights and y represents the number of 10 lb weights,

So, total weight of 3 lb weights = 3x

And, the weight of 10 lb weights = 10y

Total weight of all his weights = 3x + 10y

According to the question,

Total weight = 50 lb,

⇒ 3x + 10y = 50

Or 3x = 50 - 10y

Which is the required equation.

Second option is correct.