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4 votes
4 votes
Find k so the distance from (-1,1) to (2,k) is 5 WILL GIVE BRAINLISET

User Jrabary
by
2.3k points

2 Answers

14 votes
14 votes

Answer:

its 6

Explanation:

1+5=6

User TuxSlayer
by
3.0k points
25 votes
25 votes

Answer:

k = -3

k =5

Explanation:

\begin{gathered}d = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}\\d = 5\\(-1,1) =(x_1,y_1)\\(2,k)=(x_2,y_2)\\\end{gathered}

d=

(x

2

−x

1

)

2

+(y

2

−y

1

)

2

d=5

(−1,1)=(x

1

,y

1

)

(2,k)=(x

2

,y

2

)

\begin{gathered}5=\sqrt{\left(2-\left(-1\right)\right)^2+\left(k-1\right)^2}\\\\\mathrm{Square\:both\:sides}:\quad 25=k^2-2k+10\\25=k^2-2k+10\\\\\mathrm{Solve\:}\:25=k^2-2k+10:\\k^2-2k+10=25\\\\\mathrm{Subtract\:}25\mathrm{\:from\:both\:sides}\\k^2-2k+10-25=25-25\\k^2-2k-15=0\\\\\mathrm{Solve\:by\:factoring}\\\\\mathrm{Factor\:}k^2-2k-15:\quad \left(k+3\right)\left(k-5\right)\\\mathrm{Solve\:}\:k+3=0:\quad k=-3\\\end{gathered}

5=

(2−(−1))

2

+(k−1)

2

Squarebothsides:25=k

2

−2k+10

25=k

2

−2k+10

Solve25=k

2

−2k+10:

k

2

−2k+10=25

Subtract25frombothsides

k

2

−2k+10−25=25−25

k

2

−2k−15=0

Solvebyfactoring

Factork

2

−2k−15:(k+3)(k−5)

Solvek+3=0:k=−3

\begin{gathered}\mathrm{Solve\:}\:k-5=0:\quad k=5\\\\k =5 , k=-3\end{gathered}

Solvek−5=0:k=5

k=5,k=−3

Explanation:

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User Alex Blakemore
by
2.4k points