Question

Solve 3x^2 = –12x – 15

Answer 1

wouldn't it be 3^2=-12-15??

Answer 2

Psssst, how far did you get ?

Answer 3

I haven't started this one yet lol

Answer 4

x=-2+i,-2-i

Answer 5

a = 3
b = 12
c = 15?
Or
a = -3
b = -12
c = -15?

Answer 6

I solved it and i got a completely off answer.

Answer 7

good

Answer 8

first write it as:
ax^2+bx+c=0

Answer 9

I already did. -3x^2 -12x - 15 = 0

Answer 10

hhhmmmm..

-3x^2 -12x - 15 = 0

is the same as:

3x^2 +12x + 15 = 0

right ?

Answer 11

Yeah lol

Answer 12

ok, so

a = 3
b = 12
c = 15

now what ?

Answer 13

what is the discriminant value ?

Answer 14

\[12 \pm \sqrt{12{^2} -4(3)(15)} \div -6\]

Answer 15

it's good practice to calculate the discriminant separately first.
what do you get for that ?

Answer 16

I ended up with \[2 \pm 6i\]

Answer 17

That's not the right answer.
It's actually pretty simple if you follow always follow some steps in the same way.
But would need your attention for that :)

Answer 18

Wassup Gorgeous

Answer 19

still no progress on this problem

Answer 20

LagrangeSon.. SHH!
SmartButLazy.. Hello, stranger.
Fiddlearound.. And I no it's not :( I can't figure it out. -.-

Answer 21

show me how you calculate the discriminant, and show all work :)

\[\Delta=(b)^2-4(a)(c)\]

Answer 22

12^2 - 4(3)(15)
144 - 12(15)
144 - 180
-36

Answer 23

OK

now this:

\[x=\frac{-(b)\pm \sqrt{\Delta}}{2(a)}\]

Use the draw tool if it's easier. It must be clear how the fraction looks - what's on top and what's on the bottom

Answer 24

Just plug a, b and the discriminant in the above and show me exactly what you get.
no skipping ahead any steps :)

Answer 25

Is it clear what needs to be done ? If not let me know

Answer 26

good

Answer 27

I meant this draw tool though :)