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# 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.

Jun 16, 2021

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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