Radicals and Roots

[School_girl]

[SQRT(13) + SQRT(8)][SQRT(13) - SQRT(8)]

Can anyone please help me with this problem...thanks!

 

[tkhunny]

[SQRT(13) + SQRT(8)][SQRT(13) - SQRT(8)]

This is such a beautiful problem. How dare you not get it? :wink:

Do you remember factoring the "Difference of Squares"? That should give you a very strong hint.

Do you know how to multiply binomials? FOIL? There's another strong hint.

Super Hint -- It's a really, really laborious way to write 5.