+118690 +118690 +118690 +118690 विषय से परेे
+118690 +118690 +118690 +118690 +118690 विषय से परेे
+118690 विषय से परेे
#2
+118690 Thanks Special,
The question is a little harder than that
If you want to simplify something like
sqrt(500)
you have to look for a square number that goes into 500
Square numbers are 1,4,9,16,25,36,.......(but 1 in not helpful)
Now 25 is a square number and it is a factor of 500 so you could use that one.
sqrt(500) = sqrt(25x20) = sqrt(25) x sqrt(20) = 5 x sqrt(20)
but 4 is a square number and it is a factor of 20 so it's not fully simplified yet.
5 x sqrt(20) = 5 x sqrt(4 x 5) = 5 x sqrt(4) x sqrt(5) = 5 x 2 x sqrt(5) = 10sqrt(5)
or you could of done it quicker because 100 is a square number and it is a factor of 500
so
sqrt(500) = sqrt(100x5) = sqrt(100) x sqrt(5) = 10sqrt(5)
Now, if you have an expression where there is a number under a square root and you can't simplify it to get rid of the square root then it is called a SURD.
For example
These are all surds: sqrt(5), 8sqrt(13), -6sqrt(200)
whereas
these are not surds 8, -3, sqrt(25)
now
you can only add or subract surds if the number under the square root is the same. It is rather like the 'like terms' of algebra.
Now you have a go at your question.
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A note for Special,
If sqrt(4) is a part of an original question, then by convention, the answer is only +2
If you put the square root in as a part of your working then the answer is + or - 2.
