Distance between two points (x1,y1) and (x2,y2) can be calculated using the formula √(x2−x1)2+(y2−y1)2
Given,
Distance between the points (x,y);(5,1)= Distance between (x,y);(−1,5)
√(5−x)2+(1−y)2=√(−1−x)2+(5−y)2
⇒(5−x)2+(1−y)2=(−1−x)2+(5−y)2
⇒52+x2−10x+12+y2−2y=12+x2+2x+52+y2−10y
⇒−10x−2y=+2x−10y
⇒12x=8y
⇒xy=23
Hence, p+q=5.