Question

Solve: w^2/3=2w^1/3+8 PLEASE HELP ME GUYS! REALLY NEED YOUR HELP!

Answer 1

\[w^{\frac{2}{3}}-2w^{\frac{1}{3}}-8=0\] is a start

Answer 2

OK

Answer 3

SO I WILL ADD 8 TO THE OTHER SIDE

Answer 4

i meant to each side

Answer 5

then this is a quadratic equation in \(w^{\frac{1}{2}}\)

Answer 6

you can do that if you like, and solve by completing the square or you can factor

Answer 7

there is simpler way let w^1/3=x
so equation becomes x^2-2x-8=0
slove for x first

Answer 8

\[(u-4)(u+2)=0\] where \(u=w^{\frac{1}{2}}\)

Answer 9

same thing @satellite73 is saying

Answer 10

then for w

Answer 11

ok

Answer 12

is it x+4=0 and x+2=0?

Answer 13

no it is \(x-4=0\) or \(x+2=0\)

Answer 14

yes yes

Answer 15

so what will my answer be? my final? (x-4)(x+2)?

Answer 16

=0?

Answer 17

no that is just a step along the way
your job is to solve for \(w\)

Answer 18

x=4, x=-2?

Answer 19

yes and now replace \(x\) by \(\sqrt{w}\)

Answer 20

i am just messed up

Answer 21

lol

Answer 22

both didn't work, i tried

Answer 23

lets go slow
don't forget what you started with:
solve for \(w\) if \[w^{\frac{2}{3}}-2w^{\frac{1}{3}}-8=0\]

Answer 24

we replace \(w^{\frac{1}{3}}\) by \(x\) and get \(x=4\) or \(x=-2\)

Answer 25

ok

Answer 26

then go back and say
\[w^{\frac{1}{3}}=4\] this means the cube root of \(w\) is 4

Answer 27

if the cube root of \(w\) is 4, then \(w=4^3=64\)

Answer 28

and if the cube root of \(w\) is \(-2\) then \(w=(-2)^3=-8\)

Answer 29

ok

Answer 30

oh i see i made a mistake above in my third post, that was my faulty sorry to confuse

Answer 31

in any case we get two possible answers for \(w\) either \(w=64\) or \(w=-8\)

Answer 32

i will try that

Answer 33

ahh on line class!

Answer 34

;D

Answer 35

THE ANSWER IS -8, BECAUSE 64 DIDN'T WORK

Answer 36

well that is simply wrong
64 works for sure

Answer 37

HOW COME?

Answer 38

you can check in the original equation
if you put \(w=64\) you get \(4^2=2\times 4+8\) i.e. \(16=8+8\) so 64 is a solution whether or not the computer agrees

Answer 39

omg

Answer 40

did you try both?

Answer 41

YES

Answer 42

YES IT DID WORK. 64 IS THE ANSWER

Answer 43

I HAVE ON MORE, I DID IT. CAN YOU PLEASE CHECK IT FOR ME?

Answer 44

sure

Answer 45

WRITE THE EQUATION OF A QUADRATIC WITH SOLUTIONS OF 1/3 AND -1/4. MY ANSWER IS 12 X^2-X-1

Answer 46

ok lets try it
\[(3x-1)(4x+1)=x^2-4x+3x-1=x^2-x-1\] yes you are right

Answer 47

i mean
\[12x^2-x-1\] yes

Answer 48

your answer is correct good work

Answer 49

gotta run, good luck