similar to FOIL: (sqrt3+sqrt5)^2

Question

johnweldon1993 · Answer

Right so

$$\large (\sqrt{3} + \sqrt{5})^2 = (\sqrt{3} + \sqrt{5})(\sqrt{3} + \sqrt{5})$$

And foil that out

Hint $\large \sqrt{a} \times \sqrt{b} = \sqrt{a \times b}$

anonymous · Answer

its just so complicated! :( @johnweldon1993

johnweldon1993 · Answer

No problem, alright, so you know how foil works right?

anonymous · Answer

its just distributing?

johnweldon1993 · Answer

Basically yes, You just take the first term in the first parenthesis, and distribute it to the second parenthesis, then do the same with the second term.

johnweldon1993 · Answer

So here, our first term in the first parenthesis is √3 right?

Distribute that into the second parenthesis

anonymous · Answer

so sqrt3 into the other sqrt3?

johnweldon1993 · Answer

Correct...so what is √3 times √3 ?

Remember that hint i gave you above

√a * √b = √(a * b)

anonymous · Answer

9

johnweldon1993 · Answer

√9...

$$\large \sqrt{3} \times \sqrt{3} = \sqrt{3 \times 3} = \sqrt{9}$$ right? which we know to be

$$\large \sqrt{9} = 3$$

anonymous · Answer

okay then what?

johnweldon1993 · Answer

Well that was only distributing it to 1 thing in the parenthesis, we still need to distribute it to the √5

anonymous · Answer

okay

anonymous · Answer

whats the answer?

anonymous · Answer

@johnweldon1993