Question

find the value of k for which the distance between the points A(k,-5) and B(2,7) is 13 units​

Answer 1

Step-by-step explanation:

Distance (AB) = 13 unit

√(2-k)² + (7+5)² = 13

(2-k)² + 12² = 13²

(4 - 4k + k²) = 169 - 144

k² - 4k + 4 = 25

k² - 4k - 21 = 0

k² - 7k + 3k - 21 = 0

k(k - 7) + 3(k - 7) = 0

(k - 7) (k + 3) = 0

k = 7 , -3