In a which quadrants of the coordinate plane do the x-and y- coordinates have opposite signs

2nd and 4th

Step-by-step explanation:

The quadrants of a coordinate plane start with the top right, and go counterclockwise from 1 to 4. In the 1st quadrant, both values are positive, eliminating that answer. In the 2nd, X is negative while Y is positive, so there is one answer. In the 3rd quadrant, both values are negative, and since they are the same this answer is also eliminated. In the 4th quadrant, the bottom right, Y is negative while X is positive. Now we have both answers, which are the 2nd and 4th quadrants.