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Mathematics 12 Online
OpenStudy (2101vainilla):

FAN AND MEDAL! PLEASE HELP WITH AT LEAST ONE I have a small quiz in Algebra 2 tomorrow and these are the questions. I don't understand 3-5 Someone please explain these to me step by step

OpenStudy (2101vainilla):

satellite73 (satellite73):

3 square the thing

satellite73 (satellite73):

\[(-2\sqrt6-\sqrt3)(-2\sqrt6-\sqrt3)\] is a first step then do the usual four multiplications

OpenStudy (2101vainilla):

I know but I checked and I keep getting the wrong answer :/

satellite73 (satellite73):

ok lets do "first" \[(-2\sqrt6)(-2\sqrt6)=?\]

OpenStudy (2101vainilla):

4sqrt 36

satellite73 (satellite73):

hmm what do we call \(\sqrt{36}\) here on earth?

OpenStudy (2101vainilla):

what do you mean?

satellite73 (satellite73):

what is the square root of thirty six?

OpenStudy (2101vainilla):

6

satellite73 (satellite73):

right

satellite73 (satellite73):

you should have not written \(\sqrt{36}\) to begin with, since \[\sqrt6\times \sqrt6=6\] as that is the meaning of \(\sqrt6\), the number you square to get \(6\)

satellite73 (satellite73):

so the "first:" is \(4\times 6=24\)

satellite73 (satellite73):

how bout the "last" \(\sqrt3\times \sqrt3\)?

OpenStudy (2101vainilla):

okay okay that makes sense so far

OpenStudy (2101vainilla):

would that be 3?

satellite73 (satellite73):

of course

OpenStudy (2101vainilla):

square root of 9 is 3

satellite73 (satellite73):

that is what it means, the number you square to get 3

satellite73 (satellite73):

ok so first and last are \(24+3=?\)

OpenStudy (2101vainilla):

okay so I add them both and get 27

satellite73 (satellite73):

yup

satellite73 (satellite73):

now you have to do "outer and inner"

satellite73 (satellite73):

here the square roots do not go away \[2\sqrt6\times \sqrt3=?\]

OpenStudy (2101vainilla):

\[2\sqrt{18}\]

satellite73 (satellite73):

yes, and there is another one, so total is \[4\sqrt{18}\] but not done yet

OpenStudy (2101vainilla):

i don't add the 18s?

OpenStudy (2101vainilla):

?

satellite73 (satellite73):

no, two apples plus two apples is four apples so \[2\sqrt{18}+2\sqrt{18}=4\sqrt{18}\] still not done though

OpenStudy (2101vainilla):

okay

OpenStudy (2101vainilla):

I always mess up on this part

satellite73 (satellite73):

since \(18=9\times 2\) you know \\[\sqrt{18}=\sqrt{9}\sqrt2=3\sqrt2\]

satellite73 (satellite73):

so all together the radical part is \(4\times 3\sqrt2=12\sqrt2\)

OpenStudy (2101vainilla):

omg, you have no Idea how long ive been trying to do this problem

OpenStudy (2101vainilla):

could you help me with four and five?

satellite73 (satellite73):

yeah simplest radical form is a bear

satellite73 (satellite73):

for 4 you have to get the radical out of the denominator multiply top and bottom by \(\sqrt[3]{3x^2}\) and see what happens

OpenStudy (2101vainilla):

I know about the radical. but how you do get the squared onto the x? Ive been struggling with that rule

satellite73 (satellite73):

you have the cubed root of 9 so if you multiply by 3 you get the cubed root of \(3^3\) which is 3

satellite73 (satellite73):

you have the cubed root of \(x\) if you multiply by the cubed root of \(x^2\) you get the cubed root of \(x^3\) which is \(x\)

satellite73 (satellite73):

it is not a "rule' you just have to figure it out

satellite73 (satellite73):

second to final answer will be \[\frac{3x\sqrt[3]{3x^2}}{3x}\]

satellite73 (satellite73):

then cancel the \(3x\) top and bottom

satellite73 (satellite73):

last one is the easiest multply top and bottom by the conjugate of the denominator the conjugate of \(5-\sqrt{x}\) is \(5+\sqrt{x}\) and this works because \[(5-\sqrt{x})(5+\sqrt{x})=5^2-x\]

OpenStudy (2101vainilla):

Omg thank you so much, you're saving my grade right now

OpenStudy (2101vainilla):

Thanks so much for the help! I really appreciate it

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