Question

3x^2-6x=4
Pls help me find the solution of the quadratic equation by completing the square...

Answer 1

Move all terms to one side
3x^2−6x−4=0

Answer 2

then?

Answer 3

\[x=\frac{-b \pm \sqrt {b^2-4ac}}{2a} \]

In this case, a=3, b=−6 and c=−4

Answer 4

then?

Answer 5

Plug in the numbers and solve for x

Answer 6

how?

Answer 7

\[x=\frac{-(-6) \pm \sqrt {-6^2-4(3)(-4)}}{2(3)}\]

Answer 8

that's as far as I can go, the rest is on you.

Answer 9

:(( pls..

Answer 10

I think I could help :-)

Answer 11

help!

Answer 12

Simplify:
\[x=\frac{6+2\sqrt{21}}{6},\frac{6-2\sqrt{21}}{6}\]

Answer:
\[x=1+\frac{\sqrt{21}}{3},1-\frac{\sqrt{21}}{3}\]

Answer 13

?-?

Answer 14

@OmaiGod do you like math? do you know how to use basic arithmetic operations? basic equation manipulations?

Answer 15

no.. help me pls..

Answer 16

... it will be very hard for you to learn if you don't have any interest in this subject... what grade are you in?

Answer 17

9

Answer 18

ok i will try what i can do for you to learn some of the basic concepts of quadratic equations...

Answer 19

do you know what do numbers and letters represent in a equation?

Answer 20

no..

Answer 21

ok... numbers are called constants... if you say 3, it is a number 3, no other values...

Answer 22

0k...

Answer 23

for letters, we are using them as variables... they can have any value of number as long as they satisfy the quality in the equations...

Answer 24

ok

Answer 25

you know linear equations?

Answer 26

yeah

Answer 27

quadratic equations?

Answer 28

yes

Answer 29

ok let's proceed to completing the square...

Answer 30

I posted my solution by private message instead of interrupting this discussion. :-)

Answer 31

what @TwinYang gave you is the Quadratic Formula used to find the solution of any quadratic equation...

Answer 32

Quadratic Formula was also derived from completing the square...

Answer 33

let's use the general equation of \(ax^2+bx+c=0\) and as @wolf1728 replied, he gave you the solution already...

Answer 34

yes a worked out solution

Answer 35

still interested @OmaiGod ?

Answer 36

yes..

Answer 37

I'm wondering just how familiar OmaiGod is with all this.
Do you know the difference between a quadratic and a linear equation?
Do you know how to graph an equation?

Answer 38

ok

Answer 39

no...

Answer 40

do you know the degree of the equation?

Answer 41

n00

Answer 42

ok that is a problem too...

Answer 43

you can determine the degree of the equation by noting the biggest exponent of the variable (letter used such as x) in the given simple equation...

Answer 44

for \(x + 3=0\), what is the degree of the equation?

Answer 45

a variable without an exponent is automatically raised to 1...

Answer 46

degree of the equation also gives you an idea of the graph of equation...

Answer 47

a degree 1 equation is also known as linear equation and represented by a straight line...

Answer 48

a degree 2 equation is also known as quadratic equation and represented by a conics such as circle, parabola, ellipse, and hyperbola...

Answer 49

still want me to continue @OmaiGod ? i think you need a lot of time to absorb all of these... it cannot be done in a single hour or class session...

Answer 50

ok we are so off tangent
I can help you by using completing the square it really is not so bad or hard

Answer 51

3x^2-6x=4
ok first we need to factor out 3
3(x^2-2x)=4
if the 3 was not there, this would be an easier problem to do

Answer 52

3(x^2-2x+______) --- 3 (____) =4
better to do it this way

Answer 53

historically let me give you a quick reason why we complete the square

Answer 54

this is x^2 (btw I am using algebra tiles to illustrate this)