Solving Quadratics by Factoring and Graphing

anonimnystefy · 2011-08-03 09:55:58

hi zee-f

your -9 solution was correct but it wasn't included because you are looking for positive solutions as bobbym explained.it was correct the first time,so don't worry about that one.

also for the #17 you take only the 7 because it is positive.you don't take -9 because it is negative.

zee-f · 2011-08-03 10:00:47

so i switch them to a positive like the -9 should be a 9 when i post it to my teacher ?

zee-f · 2011-08-03 10:02:52

hey

is the work that i did correct ?am worried that am in the wrong track

anonimnystefy · 2011-08-03 10:02:59

no,no,if you change them to positive they wouldn't be correct answers.the negative ones i think should not be posted.

has your teacher told you anything about negatives in these problems?

anonimnystefy · 2011-08-03 10:04:08

the work is correct.don't worry about it.

zee-f · 2011-08-03 10:07:51

so i shouldn't swich to positive ?like how i did earlier ?for #15?

anonimnystefy · 2011-08-03 10:09:19

i already told you that you shouldn't do that,so no you don't switch negative to positive.

zee-f · 2011-08-03 10:12:23

yeah but whats really confusing me the question is asking for positive integers for 15 so is what i did in post 175 right for that question or what i did in 173 ?

anonimnystefy · 2011-08-03 10:14:27

the only answer that is asked is the positive one which is 8.

but if it told you to look at all integers and not just the positive ones than it would be 8 and -9.

anonimnystefy · 2011-08-03 10:21:06

i am sorry i have to go.see you tomorrow.

zee-f · 2011-08-03 10:25:16

so i should post the what i did in post 173?

zee-f · 2011-08-03 10:26:16

ok see you thank you for your help

bobbym · 2011-08-03 13:22:42

Hi zee-f;

In answer to your question, repost any questions that are still bothering you.

zee-f · 2011-08-04 01:02:29

hey bobbym the question that are still bothering me are 15 and 17

15- The product of two consecutive positive integers is 72. Find the integers.

17-The product of two consecutive odd integers is 63. Write a quadratic equation that you could solve to find the integers, then find the integers.

bobbym · 2011-08-04 01:24:16

I solved both of them for you earlier, what are you having a problem with?

zee-f · 2011-08-04 01:28:32

am confused like i solved two ways for 15 like is what i did in post 173 what i should post to my teacher ?

bobbym · 2011-08-04 01:34:02

Your solution was incorrect if I remember. Please bring it down to the front so everyone can see it.

zee-f · 2011-08-04 01:38:18

n(n+1)=72

n^2+n-72=0

-72+n+n^2=0

(-9+-1n)(8+-1n)=0

-9+-1n=0

-9+9-1n=0+9

-1n=9

n=-9

8+-1n=0
8+-8+-1n=0+-8

-1n=-8
n=8

n=-9,8

zee-f · 2011-08-04 01:47:06

8+-1n=0

8+-8+-1n=0+-8

-1n=-8

n=8

9+-1n=0

9+-9+-1n=0+9

-1n=-9

n=9

n=9,8

bobbym · 2011-08-04 01:48:49

What does 15 ask for?

15. The product of two consecutive positive integers is 72. Find the integers.

I am getting x = 8 so the other number is x + 1 which is 9.

Your answer should be 8,9 just as what was said previously.

What do you think it is?

zee-f · 2011-08-04 01:57:00

two consecutive positive integers

bobbym · 2011-08-04 01:57:55

Please read the previous post #195

zee-f · 2011-08-04 02:05:58

i think what i did in post 194 was correct

bobbym · 2011-08-04 02:07:10

What did you get for an answer?

zee-f · 2011-08-04 02:13:38

9,8

8+-1n=0

8+-8+-1n=0+-8

-1n=-8

n=8

9+-1n=0

9+-9+-1n=0+9

-1n=-9

n=9

n=9,8

Math Is Fun Forum

#176 2011-08-03 09:55:58

Re: Solving Quadratics by Factoring and Graphing

#177 2011-08-03 10:00:47

Re: Solving Quadratics by Factoring and Graphing

#178 2011-08-03 10:02:52

Re: Solving Quadratics by Factoring and Graphing

#179 2011-08-03 10:02:59

Re: Solving Quadratics by Factoring and Graphing

#180 2011-08-03 10:04:08

Re: Solving Quadratics by Factoring and Graphing

#181 2011-08-03 10:07:51

Re: Solving Quadratics by Factoring and Graphing

#182 2011-08-03 10:09:19

Re: Solving Quadratics by Factoring and Graphing

#183 2011-08-03 10:12:23

Re: Solving Quadratics by Factoring and Graphing

#184 2011-08-03 10:14:27

Re: Solving Quadratics by Factoring and Graphing

#185 2011-08-03 10:21:06

Re: Solving Quadratics by Factoring and Graphing

#186 2011-08-03 10:25:16

Re: Solving Quadratics by Factoring and Graphing

#187 2011-08-03 10:26:16

Re: Solving Quadratics by Factoring and Graphing

#188 2011-08-03 13:22:42

Re: Solving Quadratics by Factoring and Graphing

#189 2011-08-04 01:02:29

Re: Solving Quadratics by Factoring and Graphing

#190 2011-08-04 01:24:16

Re: Solving Quadratics by Factoring and Graphing

#191 2011-08-04 01:28:32

Re: Solving Quadratics by Factoring and Graphing

#192 2011-08-04 01:34:02

Re: Solving Quadratics by Factoring and Graphing

#193 2011-08-04 01:38:18

Re: Solving Quadratics by Factoring and Graphing

#194 2011-08-04 01:47:06

Re: Solving Quadratics by Factoring and Graphing

#195 2011-08-04 01:48:49

Re: Solving Quadratics by Factoring and Graphing

#196 2011-08-04 01:57:00

Re: Solving Quadratics by Factoring and Graphing

#197 2011-08-04 01:57:55

Re: Solving Quadratics by Factoring and Graphing

#198 2011-08-04 02:05:58

Re: Solving Quadratics by Factoring and Graphing

#199 2011-08-04 02:07:10

Re: Solving Quadratics by Factoring and Graphing

#200 2011-08-04 02:13:38

Re: Solving Quadratics by Factoring and Graphing

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