Question

The straight line joining the points p (9,-1) and Q (k,5) has a gradient of-3 ,find the value of k.

Answer 1

Answer:

k = 7

Step-by-step explanation:

Given :- Points P(9,-1) and Q(k,5)

             and gradient m = -3

To Find :- value of k

Solution :-  we know that, gradient m = $\frac{y2 -y1}{x2 -x1}$

∴   -3 = $\frac{5+1}{k-9}$

∴   -3 = $\frac{6}{k-9}$

∴   -3k +27 = 6

∴  -3k = -21

∴   3k = 21

⇒ k =  7