TSwizzle
an you please show me how to solve an equation like this?! It's not making sense. x² + 6x = –5
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abb0t
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Add the 5 and set your polynomial to zero.
TSwizzle
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1
x² + 6x + 5 = 0?
abb0t
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2
\[x^2+6x+5 =0\]
notice that it's in the form: \[ax^2+bx+c\]
to factor, you must find TWO numbers whose product is "c", but the sum of the two terms, result in "b". Does that make sense?
It means: n x n = c, but n + n = b
abb0t
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where the n's are two constants. meaning numbers - obviously.
TSwizzle
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Um...still don't get it.
Khaleesi
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you have to find two numbers whose product is 5 and sum is 6
TSwizzle
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Oh! Okay!
abb0t
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Yes.
TSwizzle
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But...that's for factoring right? I need to find the value of x...
Khaleesi
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yea, you can solve for x by factoring
abb0t
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Yes, to find the value(s) of "x". You need to factor.
Khaleesi
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or you can use the quadratics formula
TSwizzle
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Okay...
abb0t
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quadratic formula usually makes the algebra more tedious. It's best if you factor.
TSwizzle
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Can you guys check my answer once I attempt to figure it out?
Khaleesi
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sure
abb0t
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Of course.
TSwizzle
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Okay, I'm coming up with jibberish. Could you walk me through it?
Khaleesi
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2
make a list of factors of 5
TSwizzle
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1
just 1 and 5
TSwizzle
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and -1 and -5
Khaleesi
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yes. so (x + 1)(x + 5) = 0
now you can set those two factors (x + 1 and x + 5) set to 0 and solve for x
Khaleesi
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right, but you couldn't use -1 and -5 because those don't add up to 6
TSwizzle
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okay
Khaleesi
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so solve for x in both
x + 5 = 0 and x + 1 = 0
and they will be your answers
TSwizzle
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1
-5 and -1?
Khaleesi
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yes :]
TSwizzle
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okay thanks!
Khaleesi
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2
no problem