Factor this expression completely, then place the factors in the proper location on the grid. 1/8x^3-1/27y^3
\[(a-b)^3=(a-b)(a^2+ab+b^2)\] Find your a and b and use the formula.
can you answer ?
i give medal
can you tell what a and b is? from your equation?
\[a^3-b^3=(a-b)(a^2+ab+b^2)\]
look on screen
i understand the problem, but i'm helping you do it, not doing it for you friend.
im stuck + this was last question of the day
solve please
its not hard, i can help you... can you tell me what a^3 is?
a squared 3
from the formula above, you need to find a and b using cube roots
i hate fractions doing in factor
\[\frac{ 1 }{ 8 }x^3-\frac{ 1 }{ 27 }y^3\] this is the formula for factoring: \[a^3-b^3=(a-b)(a^2+ab+b^2)\] You need to find the a and the b. what times itself 3 times gives 8 and what times itself gives 27?
then pretend they're not fractions, just use the denominator for now pretend its 8x^3-27y^3
what is the cube root of 8 and what is the cube root of 27?
The cube root of 8 is 2
good
for 27 is 3
good. so use the formula with a=2x and b=3y \[a^3-b^3=(a-b)(a^2-ab-b^2)\] \[8x^3-27y^3=(2x-3y)((2x)^2+(2x)(3y)+(3y)^2)\] The only difference with your problem is the numbers will be denominators with 1 as the numerator.
i have to put 1/6x in grid with they answer
yes the answer will have a 1/6 in it somewhere
actually it should be 1/6xy
1/216 (3x-2y)(9x^2+6xy+4y^2) that's what comes up to me
\[8x^3−27y^3=(2x−3y)((2x)^2+(2x)(3y)+(3y)^2)\] \[(2x−3y)((2x)^2+(2x)(3y)+(3y)^2)\] is the part that needs calculating. The first two terms are done, now what is the first term of the second part of the parenthesis (2x)^2?
4x^2?
yes... so what's the rest?
(4x^2 + 6xy + 9y^2) is the last part... therefore \[8x^3-27y^2=(2x-3y)(4x^2+6xy+9x^2)\] the only difference is now all the numbers are under the fraction with a 1 on top.
8^3-6xy-27Y^3=9y^2
?
\[\frac{ 1 }{ 8}x^3-\frac{ 1 }{ 27}y^3=(\frac{ 1 }{ 2}x-\frac{ 1 }{ 3}y)(\frac{ 1 }{ 4}x^2+\frac{ 1 }{ 6}xy+\frac{ 1 }{ 9}y^2)\]
thats the answer?
yeah
their is no 1/8 in box look
its the problem and the answer together
i need put answer on grid can you type your answer so it will fit the gird look on screen
ok the right of the equal sign is the answer, the left of the equal sign is the orginal problem
ok got it :)
are you teacher? in past or right now :) your good explaining
yes i am just here to help people
thanks
its just a formula you plug the numbers in claylordmath, you're making it way harder than it is. i know it looks scary but its not really that hard.
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