Question

If the slope of the line joining the points (2k, -2) and (1, - k) be (-2), find k​

Answer 1

k=4/5

Explanation:

(-k+2)/(1-2k) = -2 ( using the slope formula (y2-y1)/(x2-x1) )

-k+2 = -2 (1-2k)

-k+2 = -2 + 4k

2= -2 +5k

4 = 5k

k=4/5

Answer 2

k = 4/5

Explanation:

To find k use the formula for finding the slope of a line and equate it to the slope which is - 2

So we have

(2k, -2) and (1, - k)

`- 2 = ( - k + 2)/(1 - 2k)`

Cross multiply

That's

- 2( 1 - 2k ) = - k + 2

Expand and simplify

- 2 + 4k = - k + 2

Group like terms

4k + k = 2 + 2

5k = 4

Divide both sides by 5

k = 4/5

Hope this helps you