Question

Multiplying and Dividing Irrationals

Answer 1

(8+√5)(8−√5)

Answer 2

(7 + √2)(8 - 3√2)

Answer 3

These are the two I am having trouble with. :/

Answer 4

@dpaInc Can you help me? :D

Answer 5

just FOIL them out...
for this one
(8+√5)(8−√5) = 64 -5 = 59

for this one:
(7 + √2)(8 - 3√2) = 56 - 21sqrt2 + 8sqrt2 - 24*2
= 56-48 - 13sqrt2

simplify...

Answer 6

be right back...

Answer 7

Kk.

Answer 8

Err... 56 - 48 - 13sqrt2 isn't an option.
:S

Answer 9

no

Answer 10

The options are 50, 50 - 13sqrt2, 50 + 28sqrt2, 3 - sqrt2

Answer 11

(7 + √2)(8 - 3√2) = 56 - 21sqrt2 + 8sqrt2 - 3*2 = 50-13sqrt2

Answer 12

Oh! :D Ok, wait... my major question is now "what are the rules for simplifying irrational numbers?"

Answer 13

Like sqrt numbers bug me. A lot.

Answer 14

\[\sqrt50 \over \sqrt5\] = \[\sqrt10\] Right?

Answer 15

@Austin_Rain , yes.

Answer 16

Alright. Thanks! :)

Answer 17

@dpaInc \[\sqrt5(8 + 3\sqrt6) = 8\sqrt5 + 3\sqrt30\]

Answer 18

@Austin_Rain , that's correct.

Answer 19

Ok :)

Answer 20

Thanks.

Answer 21

sorry man I was out again...

Answer 22

I see. :P