Question

Find k so that the distance from (–1, 1) to (2, k) is 5 units.

Answer 1

Answer:

distance formula = √(x2-x1)^2 + (y2-y1)^2

It is given that , distance = 5

and , x1= -1 , x2 = 2 , y1 = 1 , y2 = k

Now, put these value in formula

5 = √(2+1)^2 + (k - 1)^2

Squaring on both sides , we get

25 = (3)^2 + (k-1)^2

25 = 9 + k^2 +1 -2k

25 = k^2 -2k + 10

15 = k^2 -2k

therefore,, k^2 -2k - 15 = 0

k^2 -5k + 3k - 15 = 0

k(k - 5) + 3(k - 5) = 0

(k+3) (k -5) = 0

therefore ,

either . k = -3 or k = 5 .

Step-by-step explanation:

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Answer 2

Answer:

5

Step-by-step explanation:

9+(k-1)*2=25

(k-1)*2=16

k-1=4

k=5