Given, distance between the points (x,0) and (−7,0)=10 units. Here, x1=x,y1=0,x2=−7 and y2=0 ∴‌‌ Required distance =√(x2−x1)2+(y2−y1)2 ⇒‌‌√(−7−x)2+(0−0)2=10 ⇒‌‌±(x+7)=10 If x+7=10, then x=3 If −(x+7)=10, then x=−17