Solve:: 6x^4 - 19x^2 + 15 = 0?

Question

Actually little miss attitude, I am checking my answers against others and I know for a fact, yours is wrong so, go purposely screw other peoples questions up.

Answer 1

Substitute x^2 = z

6z^2 - 19z + 15 = 0

Solve for all z's

Then... use x^2 = z to solve for all x's

6z^2 - 19z + 15 = 0
(3z - 5)(2z - 3) = 0

z = 5/3 .... z = 3/2

x^2 = z
x = ±√z

x = ±√(5/3)..... x = ±√(3/2)


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Dont mind Nandina. She probably just doesnt understand the question and is jealous of people that can work it out or has the inquisitiveness to ask.

I get frustrated with people who ask all their homework questions too... but some people actually ignorantly believe that any and all math questions must be someones homework. Why? Because why else would anyone DO a math problem in the first place?

Ha ha... that attitude only proves stupidity. I have asked many math questions on here this past week alone... and Im in between college quarters right now.

Answer 2

6x^4 - 19x^2 + 15 = 0
=> 6x^4 - 10x^2 - 9x^2 + 15 = 0
=> 2x^2 ( 3x^2 - 5 ) - 3 ( 3x^2 - 5 ) = 0
=> ( 2x^2 - 3 ) ( 3x^2 - 5 ) = 0

=> x^2 = 3/2 or 5/3

=> x = (+ or -)sqrt (3/2) or (+or-)sqrt(5/3)

Answer 3

Hint let u=x^2 and substitute to get 6u^2-19u+15=0.

Solve this for u then square root each answer (remembering that you get a postive and negative answer for each) to get the x values.

Answer 4

say a = x^2

you get 6a^2 - 19a + 15 = 0

now applying the quadratic formula of (-b+/-sqrt(b^2-4ac))/2a gives...

(19 +/- sqrt(361-360)) / 12 = (19 +/- 1)/12

a = 20/12 or 18/12 = 5/3 or 3/2

therefore recalling a = x^2, x = sqrt(a)

so x = sqrt(5/3) or sqrt(1.5)

Answer 5

( 3 x ² - 5 ) ( 2 x ² - 3 ) = 0
x ² = 5 / 3 , x ² = 3 / 2
x = ± √( 5 / 3 ) , x = ± √( 3 / 2 )

Answer 6

x=16.5

And if you're willing to take a complete stranger's answer instead of doing your own homework, you deserve whatever grade you get.