Question

Multiply and simplify:

Answer 1

is this the answer

Answer 2

that's not what I got...
let me double check.

Answer 3

No, look:
first FOIL\[(7+3\sqrt2)(9-5\sqrt2)\]\[=(9*7)+(9*3)\sqrt2-(5*7)\sqrt2-(5*3)\sqrt2*\sqrt2\]note that \[\sqrt2*\sqrt2=2\]so we have\[=63+18\sqrt2-35\sqrt2-(15*2)\]combining like terms gives\[=63-30+(18-35)\sqrt2=33-17\sqrt2\]I hope you study this to find your mistake.

Answer 4

so its

Answer 5

yes it is,
but that's not what I wrote....
looks like I messed up too XD

Answer 6

lol :) ur amazing!

Answer 7

oh yes, 9x3 is 27, not 18...
No, look:
first FOIL\[(7+3\sqrt2)(9-5\sqrt2)\]\[=(9*7)+(9*3)\sqrt2-(5*7)\sqrt2-(5*3)\sqrt2*\sqrt2\]note that \[\sqrt2*\sqrt2=2\]so we have\[=63+27\sqrt2-35\sqrt2-(15*2)\]combining like terms gives\[=63-30+(27-35)\sqrt2=33-8\sqrt2\]oops...

Answer 8

forget the "no, look" part above
it's a copy-paste

Answer 9

ok :)