SOLUTION: How do I solve this problem? (Sqrt of 3 + sqrt of 5)(sqrt of 3 + sqrt of 5) This is multiplication...

Question 719087: How do I solve this problem?
(Sqrt of 3 + sqrt of 5)(sqrt of 3 + sqrt of 5)
This is multiplication...
Answer by jsmallt9(3758) (Show Source): You can put this solution on YOUR website!

Don't let the square roots distract you. This is one two-term expression times another two-term expression. You can use FOIL to multiply them.

But if we look closer, the two two-term expressions are exactly the same. We could rewrite the expression as:

So not only can we use FOIL we can use a factoring pattern:

to multiply. Using the pattern is faster and easier than FOIL so I will use the pattern. In our expression, our "a" is and our "b" is . So according to the pattern

will be equal to

Simplifying...

This is the answer. (If you had used FOIL correctly you would have gotten the same thing.)
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