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The product \((3-\sqrt{5})(4+2\sqrt{5})\) can be expressed in the form \(a+b\sqrt{5}\), where a and b are integers. Find a+b.

 Jun 16, 2021
 #1
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\((3-\sqrt5)(4+2\sqrt5) = 12-4\sqrt5+6\sqrt5-2(5)\)

                                     \(=2+2\sqrt5\)

\(a+b\sqrt5= 2+2\sqrt5\)

 

Comparing both sides, 

\(a= 2\)  and \(b=2\)

\(a+b=4\)

 

 

~I hope its clear now :) 

 Jun 16, 2021

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