Question

Find the roots of the equation. Round to tenths place, if necessary.
3x2 + 18x - 12 = 0
(Points : 4)
{-1.2, 1.2}
{1.2, 6.6}
{-6.6, 0.6}
No real solution

Answer 1

@SolomonZelman

Answer 2

\(\large\color{black}{ \displaystyle 3x^2 + 18x - 12 = 0}\)

1) factor this equation out of 3.

Answer 3

so -3 both sides

Answer 4

I mean divide every term in this equation by 3.

Answer 5

\(\large\color{black}{ \displaystyle \color{red}{\frac{\color{black}{3x^2}}{3}} + \color{red}{\frac{\color{black}{18x}}{3}} - \color{red}{\frac{\color{black}{12}}{3}} = \color{red}{\frac{\color{black}{0}}{3}}}\)

Answer 6

see what how I am dividing ?

Answer 7

yea
i see

Answer 8

so what do you get after you divide this way /

Answer 9

that first one x out

Answer 10

1+6 -4 =3

Answer 11

well, you would cancel terms on top and bottom of each fraction..... wouldn't you?

\(\large\color{black}{ \displaystyle \color{red}{\frac{\color{black}{3x^2}}{3}} + \color{red}{\frac{\color{black}{18x}}{3}} - \color{red}{\frac{\color{black}{12}}{3}} = \color{red}{\frac{\color{black}{0}}{3}}}\)

\(\large\color{black}{ \displaystyle \color{red}{\frac{\color{black}{\cancel{3}x^2}}{\cancel{3}}} + \color{red}{\frac{\color{black}{\cancel{(3)}6x}}{\cancel{3}}} - \color{red}{\frac{\color{black}{\cancel{(3)}4}}{\cancel{3}}} =0}\)

Answer 12

1.2,6.6 is that the answer

Answer 13

so, yes, you would be getting

\(\large\color{black}{ \displaystyle x^2 + 6x - 4 = 0}\)

Answer 14

I don't know yet

Answer 15

how did you get the above answers ?

Answer 16

i just guessed

Answer 17

don't guess.

Answer 18

\(\large\color{black}{ \displaystyle x^2 + 6x - 4 = 0}\)

use quadratic formula.

Answer 19

Again, the QUADRATIC FORMULA says:
\(\normalsize\color{ slate }{\Huge{\bbox[5pt, lightcyan ,border:2px solid black ]{ \LARGE{x=~} \huge{ \frac{-\color{magenta}{b} \pm\sqrt{ \color{magenta}{b} ^2-4 \color{blue}{a} \color{red}{c}}}{2 \color{blue}{a}} }~ }}}\)

when the equation is \(\LARGE\color{black}{ \color{blue}{a} x^2+ \color{magenta}{b}x+ \color{red}{c}=0 }\).

Answer 20

-1.2 , 1.2

Answer 21

I don't know what the answer is yet (and nor do you).
GUessing is not very effective.

Answer 22

try plugging your equation into the QUADRATIC FORMULA.

Answer 23

ok

Answer 24

I will help you that in your case
a = 1
b = 6
c = -4

Answer 25

ax^2+b6x-c4=0

Answer 26

a=1
b-6
c=-4

Answer 27

it is

1. (1) x^2 + (6) x + (-4) = 0

Answer 28

\(\large\color{black}{ \displaystyle ~~\color{green}{1}~x^2 + \color{red}{6}~x + (\color{blue}{-4}) = 0 }\)

\(\large\color{green}{ \displaystyle ~\downarrow }\) \(\large\color{red}{ \displaystyle ~\downarrow }\) \(\large\color{blue}{ \displaystyle ~\downarrow }\)

\(\large\color{green}{ \displaystyle ~a }\) \(\large\color{red}{ \displaystyle ~b }\) \(\large\color{blue}{ \displaystyle ~c }\)

Answer 29

Is it easy to see "a" "b" and "c" that you are supposed to plug into the quadratic formula like this?

Answer 30

Now go ahead and plug it in.
I will be back in 5-10 minutes.

Answer 31

i already got the answer its c