Question #cf444

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Answer 1 · 2017-08-19T04:48:29

#k=+-2#

Assuming you are asking about the equation:

#sqrt87.49 +sqrt(5+k^2) = 12.3#

(yours is a little hard to read...)

Step 1) square root #86. 49#

#sqrt87.49 +sqrt(5+k^2) = 12.3#

#9.3 +sqrt(5+k^2) = 12.3#

Step 2) Put all the variables on the left side of the equation and real numbers on the right

#sqrt(5+k^2) = 12.3-9.3#

#sqrt(5+k^2) = 3#

Step 3) square both sides

#(sqrt(5+k^2))^2 = 3^2#

#5+k^2=9#

Step 4) put the variables on the left and real numbers on right

#k^2=9-5#

#k^2=4#

Step 5) square root both sides

#k=+-2#

#+-# means that the answer is #2 and - 2# since that by square rooting a number, you get the positive and negative of that answer...

Unless specified, it's best you put BOTH the negative and positive answer