use the quadratica formula to solve each equation.?

Question

as you can see i alredy asked other questions, and yeah this is my homework, but i'm just askinf one out of 20, of each type to have an idea how to do the rest. thanks for helping me out with this problems. here is the question.

-2d^2+8d=0

this is the last one so thank you very much for you help again.

Answer 1

-2d^2+8d=0

simplifying the equation d^2-4d=0
further simplifying d(d-4)=0 d=0 or d-4= 0 d=4

0 and 4 are the possible roots

the second answer is wrong here my proof:

-b^2+/-sqrt b^2-4ac/2a
the correct equation is

x= (-b+/-(sqrt b^2-4ac))/2a

x= (-8+/- sqrt 8^2-4(-2)(0)))/2(-2)

x= (-8+/- sqrt 64-0)/-4

x= (-8+/- 8)/-4

x= (-8+8)/-4 or x= (-8-8)/-4

x= 0/-4 --> x=0 or x= (-16)/-4 ----> x=4

Answer 2

-2d^2+8d=0
We can change the eqn. as 2d^2-8d=0
Taking 2d commo0n i.e. 2d(d-4)=0
We get that each 2d=0, d-4=0
i.e. d=0, d=4
Hence both the values 0 and 4 are the solutions of the given equation

Answer 3

-2d^2 + 8d = 0
divide everything by -2
d^2 - 4d = 0
find half of 4, square it, and add to both sides
d^2 - 4d + 4 = 4
factor the left side into a perfect square
(d - 2)^2 = 4
sqrt both sides
d - 2 = -2 or 2
add 2 to both sides
d = 0 or 4

ANS : d = 0 or 4

Answer 4

-2d^2+8d+0=0
-b^2+/-sqrt b^2-4ac/2a
-8^2+/-sqrt 8^2-4*(-2)*0/2*-2
-64+/-sqrt(64)/-4
-64+/-8/-4
-64+8/-4=-56/-4=14
-64-8/-4=-72/-4=18
so answer seems easy d= 14 and or 18
but if u check either of the answers (i.e. plug 14 or 18 in for d you do not get zero) the equation does not seem to work. Either my math is wrong or quadratic isn't the way to do it.
sorry

Answer 5

-2d^2+8d=0
8d=2d^2
2d=d^
d=2 or d=0