Formula of Distances =
![\sqrt{(x1 - x2)^(2) + (y1 + y2)^(2) }](https://img.qammunity.org/2019/formulas/mathematics/middle-school/zd3fetyqa9r2f3cxajslqiocx2y8pohbt6.png)
So we know that Point B has the coordinates (5,2), the x-coordinate of Point A is -7 (this equal to (7,?)) and the distances between both is 13. So, right know ,we just replace everything with our data:
(x1,y1)= (5,2)
(x2,y2)=(-7,?)