Question

Find the value of K so that line passing through the points (k,-1) and (-2,8) is parallel to the equation 3x+y=-7

Answer 1

k =1

Explanation:

3x + y = -7

y = -3x - 7

m = -3

Parallel lines have same slope

`Slope = -3\\\\(8-[-1])/(-2-k)=-3\\\\\\(8+1)/(-2-k)=-3\\\\(9)/(-2-k) = -3`

Cross multiply,

9 = -3(-2-k)

9 = 6 + 3k

9-6 = 3k

3 = 3k

3/3 = k

k = 1