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OpenStudy (anonymous):

help please! what is the simplest form of the expression ?

OpenStudy (anonymous):

\[\sqrt[3]{45}+\sqrt[3]{2058}-\sqrt[3]{750}\]

OpenStudy (ranga):

Find prime factors of each of the numbers within the cube root: 45 = 3 x 3 x 5 2058 = 2 x 3 x 7 x 7 x 7 750 = 2 x 3 x 5 x 5 x 5 Take the cube root of each and evaluate the expression and simplify.

OpenStudy (anonymous):

\[\sqrt[3]{9}.\sqrt[3]{5} + \sqrt[3]{343}.\sqrt[3]{6} - \sqrt[3]{125}.\sqrt[3]{6}\]\[\sqrt[3]{9} . \sqrt[3]{5} + 7 . \sqrt[3]{6} - 5 . \sqrt[3]{6}\]\[\sqrt[3]{9} . \sqrt[3]{5} + 2\sqrt[3]{6}\]

OpenStudy (anonymous):

can you explain how you got that?

OpenStudy (anonymous):

so wat i did was that i took the 45 and broke it up into 9 and 5, then i took 2058 and broke it up into 343 and 6, then i took 750 and broke it up into 125 and 6

OpenStudy (anonymous):

because 9x5 = 45 343x6=2058 and 125 x 6 = 750 cool?

OpenStudy (anonymous):

yeah i got it. thanks you

OpenStudy (anonymous):

ok and u understand everything i did after that?

OpenStudy (anonymous):

nope can you explain that too

OpenStudy (anonymous):

ofc!

OpenStudy (anonymous):

next the cude root of 343 is 7 and the cude root of 125 is 5

OpenStudy (anonymous):

and then after that 7 times the cude root of 6 minus by 5 times the cude root of 6 = 2 times the cube root of 6

OpenStudy (anonymous):

thank you! can you help me on a few more questions i got wrong

OpenStudy (anonymous):

yea np :)

OpenStudy (anonymous):

\[\sqrt[3]{108}+\sqrt[3]{1372}-\sqrt[3]{500}\]

OpenStudy (anonymous):

would u rather we do it together or u prefer that i do it and then explain?

OpenStudy (anonymous):

together

OpenStudy (anonymous):

ok so look at the 3 cude roots and see if there is a number that u can break it up into so that u can find the cude root of it example\[\sqrt[3]{750}=\sqrt[3]{125}\sqrt[3]{6}=5\sqrt[3]{6}\]

OpenStudy (anonymous):

in this case i broke 750 into 125 and 6 cause i knew the cude root of 125 is 5

OpenStudy (anonymous):

okay then what

OpenStudy (anonymous):

well i want u to tell me if any of them could be splitted up to do that

OpenStudy (anonymous):

a hint is that\[\sqrt[3]{500}\]could be broken up into two numbers and one of them u can find the square root of, try and tell me wat aare those two numbers

OpenStudy (anonymous):

7.937?

OpenStudy (anonymous):

im sry but i have to go :/ ill be back in 30mins, hopfully u'll still be here

OpenStudy (anonymous):

i will

OpenStudy (anonymous):

back

OpenStudy (anonymous):

okay

OpenStudy (anonymous):

do you know how to do surds?

OpenStudy (anonymous):

whats that

OpenStudy (anonymous):

basically wat u have to know to do this question

OpenStudy (anonymous):

like Let C = A x B therefore \[\sqrt{C} = \sqrt{A}\sqrt{B}\]

OpenStudy (anonymous):

i have no idea

OpenStudy (anonymous):

ok well this is something u have to just accept Learn that if two numbers are being multiplied and they are square rooted example \[\sqrt{2 x 3}\] that is equal to the square root of them separatly, example \[\sqrt{2}\sqrt{3}\] Therefore \[\sqrt{2 x 3} =\sqrt{2}\sqrt{3}\]

OpenStudy (anonymous):

understand?

OpenStudy (anonymous):

yes

OpenStudy (anonymous):

cool so how you are going to use this is that if u are told to simplify the following \[\sqrt{50}\] then you'll use surds to do this \[\sqrt{25x2}\]\[\sqrt{25}\sqrt{2}\]\[5\sqrt{2}\] cool?

OpenStudy (anonymous):

yes

OpenStudy (anonymous):

so back to ur question\[\sqrt[3]{108}+\sqrt[3]{1372}-\sqrt[3]{500}\]

OpenStudy (anonymous):

now i want u to simplify \[\sqrt[3]{500} \] using that method

OpenStudy (anonymous):

how's it going?

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