Find the exact solution to 6x^2+1=-8x by using the Quadratic Formula.

Question

A)-4+-(sqrt10)
B)-4+-(sqrt22)/6
C)-2+-2(sqrt10)/3
D)-4+-(sqrt10)/6
I chose C

x=-b+-(sqrtb^2-4ac)/2a
x=--8+-(sqrt-8^2-4(6)(1))/2(6)
x=8+-(sqrt64-24)/12
x=8+-(sqrt40)/12
x= C

Answer 1

correct

Answer 2

In the first one a = 6, b = 8 and c = 1
x = [-8 +-sqrt (64-24)]/12
=[-8 +-sqrt(4*10)]/12
=[-8 +-2sqrt(10)]/12
=[-4 +-sqrt10]/6
So your amswer is wrong.

Answer 3

Thanks for picking up on that
As George would have said,
"I guess I mislooked"

Answer 4

Please explain x = [-8 +-sqrt (64-24)]/12
=[-8 +-sqrt(4*10)]/12

Answer 5

64 - 24 = 40 = 4*10

Answer 6

I did all the steps

Answer 7

i don't understand

Answer 8

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(64-24) ] / 12
x = [ -8 +/- sqrt (4*10) ] /12
x = [ -8 +/- 2 sqrt (10) ] / 12
x = [ -4 +/- sqrt(10) ] / 6
I agree with drwls :)

Answer 9

Which don't you understand:
64-24 = 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.