Solmyr
What are the solutions of x2 + 5x − 24 = 0? Show all work for full credit.



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muhammad9t5
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do it by factorizing...

hartnn
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hint : split the middle term as
8x3x

muhammad9t5
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break 5x in two terms.

muhammad9t5
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8x3x

Solmyr
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would it be
−b±/b^2  4ac

2a

hartnn
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thats using Quadratic formula...are u asked to use that ?
if not factorizing will be better approach

Solmyr
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ya its asking for quadratic formula

hartnn
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Compare your quadratic equation with \(ax^2+bx+c=0\)
find a,b,c
then the two roots of x are:
\(\huge{x=\frac{b \pm \sqrt{b^24ac}}{2a}}\)

hartnn
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so, first tell me what u get for a,b,c.

Solmyr
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a=x^2
b=5
c=24

hartnn
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no, 'a' is the coefficient of x^2
here u have 1x^2
so a=.... ?

Solmyr
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1^2

hartnn
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dw:1356626845466:dw

Solmyr
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a=1
b=5
c=24

hartnn
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are u sure about the value of 'c' ?

Solmyr
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24

hartnn
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correct, now just plug in the values of a,b,c in that quadratic formula

Solmyr
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−b±/b^2  4ac

2a
5 +/5^2  4 * 1 * 24

2
5 +/ 25  96

2

Solmyr
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5 /5^2  4 * 1 * 24

2
5 / 25  96

2

hartnn
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remember that c=24
so
\(b^24ac = 254(1)(24) = 25+96=...?\)

Solmyr
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i cant believe i keep messing that up

hartnn
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everything else was correct.

Solmyr
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121

hartnn
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yes, and \(\sqrt{121}=..?\)

Solmyr
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11 SR

Solmyr
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5 + 11= 6
 = 3
2

hartnn
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yes, and (511)/2 =... ?

hartnn
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?

Solmyr
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8

hartnn
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thats correct, so 2 roots are 3 and 8.

Solmyr
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ok thank u for all ur help

hartnn
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welcome ^_^