Question

If the distance between the points A(–3, –14) and B(a, –5) is 9 units, then a = ______.

Answer 1

If the distance between the points A(–3, –14) and B(a, –5) is 9 units, then a = –3.

Explanation:

Distance AB = `sqrt((a - (-3))^2 + (-5 - (-14))^2)` 

= `sqrt[(a + 3)^2 + 9^2)` 

= 9

Squaring: (a + 3)² + 81 = 81 

⇒ (a + 3)² = 0 

⇒ a = –3