Question #cbd01

1 Answer
Kevin B.
Aug 12, 2017

You are correct that the answer is #2#. You can do operations to both sides of the equation to isolate #a# on one side. #root(2)#

Explanation:

We start off with this equation:

#sqrt(2+a) = 2# (A note here, usually when there is a root symbol and the index number is not explicitly written, we assume that it means "square root" = index #2# = #root(2)#.)

We can square both sides of the equation to get
#(sqrt(2+a))^2 = 2^2#
#2+a = 4#

Now we can subtract #2# from both sides and clearly see that #color(blue)(a = 2)#.

Checking Answers
Every time you square both sides of an equation, it's good practice to plug your answer back in to make sure that it works.

#sqrt(2+color(blue)(2)) = 4#

So our solution works.

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