Solving Quadratics by Factoring and Graphing

zee-f · 2011-08-07 05:35:23

she doesn't want it in fraction form so i multiplied the whole thing by 2 did i do it correct

(x+1)(x-8)=0

(x^2-7x-8)

bobbym · 2011-08-07 05:38:34

Hi;

If you multiply the right hand side you do not get your answer. Please try again.

zee-f · 2011-08-07 06:25:09

(2x+1)(x-4)

2x^2-3x-4

bobbym · 2011-08-07 06:26:38

Hi;

That is correct! But your multiplication of it is not.

zee-f · 2011-08-07 06:35:19

2x^2-3x-4

zee-f · 2011-08-07 06:36:20

2x*x=2x^2
1+-4=3
1*-4=-4

bobbym · 2011-08-07 06:37:45

Hi;

Please check post #254. That is the correct answer. Your teacher has you doing all kinds of machinations but she has not taught you how to multiply two binomials. Now I know why people hate math, they must all have had your teacher.

zee-f · 2011-08-07 06:43:27

yeah math is hard because she doesn't explain right

zee-f · 2011-08-07 06:45:06

i get it u added the 2 thats what i missed

bobbym · 2011-08-07 06:47:25

She makes me hate doing math!

Is it a little clearer the multiplication?

You will need some practice in that.

zee-f · 2011-08-07 06:54:20

yup its clearer thank you and i am doing some practices am also looking at the links in mathisfun there pretty helpful

bobbym · 2011-08-07 15:10:02

Hi zee-f;

Try this one for me:

zee-f · 2011-08-08 06:27:18

hey bobbym see i posted the work we did like the way u tough me to do it and this is her reply to me
#12. When you multiply by 2, make sure you multiply 2(x + 1/2)(x - 4). Try this.

bobbym · 2011-08-08 06:46:40

What does she want you to multiply?

zee-f · 2011-08-08 06:59:17

she said she doesn't want it in the fraction form so she told me to multiply the equation by 2 to get rid of the fraction

bobbym · 2011-08-08 06:59:59

Did you multiply both sides?

zee-f · 2011-08-08 07:02:14

so i would get (2x+1)(2x-8)

bobbym · 2011-08-08 07:03:17

No, you only multiply one of them!

zee-f · 2011-08-08 07:10:23

i did it the way u told me to and i think your way makes more sense but when i did it she said
#12. When you multiply by 2, make sure you multiply 2(x + 1/2)(x - 4). Try this.

am just ganna do as she asked to get the full grade so if i multiply it her way ill get (2x+1)(2x-8)

bobbym · 2011-08-08 07:12:15

Why are going to get (2x+1)(2x-8)?

You get (2x+1)(x-4)

zee-f · 2011-08-08 07:15:29

thats what posted to her(2x+1)(x-4)

she said its incorrect

bobbym · 2011-08-08 07:16:03

Did you multiply the other side of the equation?

zee-f · 2011-08-08 07:27:36

i posted this to her (2x+1)(x-4)

but she said When you multiply by 2, make sure you multiply 2(x + 1/2)(x - 4)
so 2*x=2x 2*1/2=1
(2x+1)
then 2*x=2x
2*-4=-8
(2x-8)

bobbym · 2011-08-08 07:33:32

Hi zee-f;

It does not equal:

It does equal:

zee-f · 2011-08-08 07:39:25

i think it kinda makes sense because i though we have to do everything we do on the right we do on the left like she said let me get it clear what i did

so the equation is this

12. Work backwards to write a quadratic equation that will have solutions of x = -1/2 and x = 4.
12. (x+1\2)(x-4)=x^2-7/2-2)

thats what i posted she said
12. Good. When we have a problem that contains a fraction, we will multiply the equation by the denominator to remove the fraction. Try this please

i posted this

#12-
(2x+1)(x-4)
(2x^2-7x-4)

her reply is this
#12. When you multiply by 2, make sure you multiply 2(x + 1/2)(x - 4). Try this.

am sooooooooo confused

Math Is Fun Forum

#251 2011-08-07 05:35:23

Re: Solving Quadratics by Factoring and Graphing

#252 2011-08-07 05:38:34

Re: Solving Quadratics by Factoring and Graphing

#253 2011-08-07 06:25:09

Re: Solving Quadratics by Factoring and Graphing

#254 2011-08-07 06:26:38

Re: Solving Quadratics by Factoring and Graphing

#255 2011-08-07 06:35:19

Re: Solving Quadratics by Factoring and Graphing

#256 2011-08-07 06:36:20

Re: Solving Quadratics by Factoring and Graphing

#257 2011-08-07 06:37:45

Re: Solving Quadratics by Factoring and Graphing

#258 2011-08-07 06:43:27

Re: Solving Quadratics by Factoring and Graphing

#259 2011-08-07 06:45:06

Re: Solving Quadratics by Factoring and Graphing

#260 2011-08-07 06:47:25

Re: Solving Quadratics by Factoring and Graphing

#261 2011-08-07 06:54:20

Re: Solving Quadratics by Factoring and Graphing

#262 2011-08-07 15:10:02

Re: Solving Quadratics by Factoring and Graphing

#263 2011-08-08 06:27:18

Re: Solving Quadratics by Factoring and Graphing

#264 2011-08-08 06:46:40

Re: Solving Quadratics by Factoring and Graphing

#265 2011-08-08 06:59:17

Re: Solving Quadratics by Factoring and Graphing

#266 2011-08-08 06:59:59

Re: Solving Quadratics by Factoring and Graphing

#267 2011-08-08 07:02:14

Re: Solving Quadratics by Factoring and Graphing

#268 2011-08-08 07:03:17

Re: Solving Quadratics by Factoring and Graphing

#269 2011-08-08 07:10:23

Re: Solving Quadratics by Factoring and Graphing

#270 2011-08-08 07:12:15

Re: Solving Quadratics by Factoring and Graphing

#271 2011-08-08 07:15:29

Re: Solving Quadratics by Factoring and Graphing

#272 2011-08-08 07:16:03

Re: Solving Quadratics by Factoring and Graphing

#273 2011-08-08 07:27:36

Re: Solving Quadratics by Factoring and Graphing

#274 2011-08-08 07:33:32

Re: Solving Quadratics by Factoring and Graphing

#275 2011-08-08 07:39:25

Re: Solving Quadratics by Factoring and Graphing

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