Answer:
Step-by-step explanation:

The <em><u>correct answer</u></em> is:
never
Explanation:
A ray is named using the endpoint first and then another point on the ray. This means that ray AB has endpoint A and point B on the ray; ray BA has endpoint B and point A on the ray. These are not the same ray, as they do not have the same endpoint.
An equation that sets two fractions equal to each other is called a proportion. A proportion is a name we give to a statement that two ratios are equal. When two ratios are equal, then the cross products<span> of the ratios are equal. Hope this helps.</span>
Keep change change [keep the first integer change the opperation and change the integer on your number or fraction ... Rember the answer takes the sign of the larger number .