Math
posted by Jon .
Find the exact solution to 6x^2+1=8x by using the Quadratic Formula.
A)4+(sqrt10)
B)4+(sqrt22)/6
C)2+2(sqrt10)/3
D)4+(sqrt10)/6
I chose C
x=b+(sqrtb^24ac)/2a
x=8+(sqrt8^24(6)(1))/2(6)
x=8+(sqrt6424)/12
x=8+(sqrt40)/12
x= C

Math 
Reiny
correct

Math 
drwls
In the first one a = 6, b = 8 and c = 1
x = [8 +sqrt (6424)]/12
=[8 +sqrt(4*10)]/12
=[8 +2sqrt(10)]/12
=[4 +sqrt10]/6
So your amswer is wrong. 
Math 
Reiny
Thanks for picking up on that
As George would have said,
"I guess I mislooked" 
Math(im confused) 
Jon
Please explain x = [8 +sqrt (6424)]/12
=[8 +sqrt(4*10)]/12 
Math 
drwls
64  24 = 40 = 4*10

Math(so how is my answer wrong? 
Jon
i don't understand

Math 
drwls
Which don't you understand:
6424 = 40, or
40 = 4 x 10?
Or my use of * for x when multiplying?
We do that often here to avoid confusion with the algebraic variable x. 
Math(please explain b/c I don't think im wrong) 
Jon
I did all the steps

Math 
Damon
a = 6
b = 8
c = 1
why did you use 8 for b?
why dis you not divide b by 2a?
you left a bracket out, wrecking everything
x = [ 8 +/ sqrt (64  4*6*1) ] /2*6
x = [ 8 +/ sqrt(6424) ] / 12
x = [ 8 +/ sqrt (4*10) ] /12
x = [ 8 +/ 2 sqrt (10) ] / 12
x = [ 4 +/ sqrt(10) ] / 6
I agree with drwls :)
Respond to this Question
Similar Questions

Math
Is this correct: sqrt2/sqrt10=sqrt2/5sqrt2 nope. it would be sqrt2/(sqrt5)(sqrt2) no.d sqrt2/sqrt10= sqrt (2/10)= sqrt (1/5) sqrt 0.2 thanks can you help me with this please? 
Algebra 1
sqrt (10/2)= sqrt 5 Quotient Property: 2*sqrt10/2 I need to learn how to simplify the expression give me a problem and i can teach you 
algebra
Can someone please check my work on this problem? 
Algebra
I got a couple I want to check my work : Both are Solve using the quadratic formula : 1) x^23x=7x2 x^23x7x+2=7x7x2+2 x^210x+2=0 x = 10 + sqrt10^2  4(1)(2) / 2(1) x = 10 + sqrt100  8 / 2 x = 10 + sqrt92 / 2 x = 10 + 2sqrt23 … 
Algebra II
Find the exact solutions to 6x^2+x+4=0 by using the quadratic formula. x=b+sqrtb^24ac/2a 1+sqrt1^24(6)(4)/2(6) 1+sqrt95/12 195/12 96/12 x= 8 1+95/12 94/12= 7.8333.. [8, 7.83](answer) 
Trig Check my answer Please
Find the unit vector in the direction of <1,2>. Do not approximate any numbers in your answer. I get (1/sqrt10) and (3/sqrt10) 
PreCalculus
Given that SIN Theta = 1/sqrt(10) and theta is in quadrant 4, find sin2theta and cos2theta. I'm not sure how to properly square the 1/sqrt10 and keep an exact answer other than decimal. Otherwise, my final answer is 1.632455533 
Precalculus check answers help!
16. Find the distance between P (–2, 5) and the line with equation x – 3y + 4 = 0. (1 point) 17(sqrt10)/ 10 0 17(sqrt10)/ 10 13(sqrt10)/ 10 ~ 17. Find the distance between the lines with equations 5x + 12y = 12 and y = –x + … 
Precalculus check answers help!
16. Find the distance between P (–2, 5) and the line with equation x – 3y + 4 = 0. (1 point) 17(sqrt10)/ 10 0 17(sqrt10)/ 10 13(sqrt10)/ 10 ~ 17. Find the distance between the lines with equations 5x + 12y = 12 and y = –x + … 
math
theta is a first quadrant angle in standard position and cos theta = 1/(sqrt10) . Find the exact value of sin theta,