Math help.

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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.

Technoblade Jun 16, 2021

amygdaleon305 · Answer 1 · 2021-06-16T06:06:44

$(3-\sqrt5)(4+2\sqrt5) = 12-4\sqrt5+6\sqrt5-2(5)$

$=2+2\sqrt5$

$a+b\sqrt5= 2+2\sqrt5$

Comparing both sides,

$a= 2$ and $b=2$

$a+b=4$

~I hope its clear now :)