Math Is Fun Forum

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Solving Quadratics by Factoring and Graphing

Hi;

12. (x+1\2)(x-4)=x^2-7/2-2)

That is incorrect, for one thing you can not use \ for / they mean different things. Also this is wrong

x^2-7/2-2, there is supposed to be an x after -7/2. I have already gone over that with you.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

zee-f

Member

Registered: 2011-05-12

Posts: 1,220

Re: Solving Quadratics by Factoring and Graphing

yup i know that i just wanted to show what she said about the work

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One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Solving Quadratics by Factoring and Graphing

Hi zee-f;

Is she a math teacher or a gym teacher substituting for one?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

zee-f

Member

Registered: 2011-05-12

Posts: 1,220

Re: Solving Quadratics by Factoring and Graphing

2(x + 0.5)(x + -4) = 0

2(0.5 + x)(x + -4) = 0

2(0.5 + x)(-4 + x) = 0

(0.5 + x) * (-4 + x)
2(0.5(-4 + x) + x(-4 + x)) = 0
2((-4 * 0.5 + x * 0.5) + x(-4 + x)) = 0
2((-2 + 0.5x) + x(-4 + x)) = 0
2(-2 + 0.5x + (-4 * x + x * x)) = 0
2(-2 + 0.5x + (-4x + x2)) = 0

0.5x + -4x = -3.5x
2(-2 + -3.5x + x2) = 0
(-2 * 2 + -3.5x * 2 + x2 * 2) = 0
(-4 + -7x + 2x2) = 0

-4 + -7x + 2x2 = 0

(-1 + -2x)(4 + -1x) = 0

i switched the 1/2 to 0.5 and solved it am ganna post it to her like this  i think makes more sense to herrrrrrrr

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One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Solving Quadratics by Factoring and Graphing

Watch out for the way you write x^2, x2 is not the same.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

zee-f

Member

Registered: 2011-05-12

Posts: 1,220

Re: Solving Quadratics by Factoring and Graphing

#12-

2(x + 0.5)(x + -4) = 0

2(0.5 + x)(x + -4) = 0

2(0.5 + x)(-4 + x) = 0

(0.5 + x) * (-4 + x)

2(0.5(-4 + x) + x(-4 + x)) = 0

2((-4 * 0.5 + x * 0.5) + x(-4 + x)) = 0

2((-2 + 0.5x) + x(-4 + x)) = 0

2(-2 + 0.5x + (-4 * x + x * x)) = 0

2(-2 + 0.5x + (-4x + x2)) = 0

0.5x + -4x = -3.5x

2(-2 + -3.5x + x^2) = 0

(-2 * 2 + -3.5x * 2 + x^2 * 2) = 0
(-4 + -7x + 2x^2) = 0

-4 + -7x + 2x^2 = 0

(-1 + -2x)(4 + -1x) = 0

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One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Solving Quadratics by Factoring and Graphing

The answer at the bottom is correct.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Solving Quadratics by Factoring and Graphing

hi zee-f

that is not correct.you can lose the 2 or even better you can first multiply 2(x+0.5)=2x+1

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

zee-f

Member

Registered: 2011-05-12

Posts: 1,220

Re: Solving Quadratics by Factoring and Graphing

-4.9t2 + 24.5t + 117.6 = 49

117.6 + 24.5t + -4.9t2 = 49

117.6 + -49 + 24.5t + -4.9t2 = 49 + -49

117.6 + -49 = 68.6
68.6 + 24.5t + -4.9t2 = 49 + -49

49 + -49 = 0
68.6 + 24.5t + -4.9t2 = 0

-14 + -5t + t2 = 0

-14 + -5t + 14 + t2 = 0 + 14

-14 + 14 + -5t + t2 = 0 + 14

-14 + 14 = 0
0 + -5t + t2 = 0 + 14
-5t + t2 = 0 + 14

0 + 14 = 14
-5t + t2 = 14

.

-5t + 6.25 + t2 = 14 + 6.25

6.25 + -5t + t2 = 14 + 6.25

14 + 6.25 = 20.25
6.25 + -5t + t2 = 20.25

(t + -2.5)(t + -2.5) = 20.25

(t + -2.5) equal to 4.5 and -4.5.

t + -2.5 = 4.5

-2.5 + t = 4.5

-2.5 + 2.5 + t = 4.5 + 2.5

-2.5 + 2.5 = 0.0
0.0 + t = 4.5 + 2.5
t = 4.5 + 2.5

4.5 + 2.5 = 7
t = 7

t = 7

t + -2.5 = -4.5

-2.5 + t = -4.5

-2.5 + 2.5 + t = -4.5 + 2.5

-2.5 + 2.5 = 0.0
0.0 + t = -4.5 + 2.5
t = -4.5 + 2.5

-4.5 + 2.5 = -2
t = -2

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One, who adopts patience, will never be deprived of success though it may take a long time to reach him. Imam ali (as)<3

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Solving Quadratics by Factoring and Graphing

Hi zee-f;

7 and -2 are correct solutions to that equation.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.