Mathematics
20 Online
zarkam21:
Help please
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zarkam21:
zarkam21:
@Vocaloid
Vocaloid:
Is this a graded test?
zarkam21:
Nope practice
zarkam21:
QC does not permit tests and quizzes, I thought?
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Vocaloid:
right, I was just making sure
Vocaloid:
anyway part I is just asking you to use foil and expand (x-5)(x+2) first
Vocaloid:
|dw:1515005559823:dw|
Vocaloid:
x*x = ?
zarkam21:
x^2
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Vocaloid:
good, now outer|dw:1515005642100:dw|
Vocaloid:
2 times x is just 2x so outer = 2x
Vocaloid:
|dw:1515005682191:dw|
inner = -5x
zarkam21:
wait so what would F be
Vocaloid:
F = first
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zarkam21:
l=last
Vocaloid:
yup
|dw:1515005732397:dw|
zarkam21:
F: First
O: 2x
I: -5x
L: Last
zarkam21:
Like this
Vocaloid:
for first you have to multiply the first term in each bracket together
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Vocaloid:
|dw:1515005780422:dw|
Vocaloid:
^ multiply x and x together to get the first
zarkam21:
(x-5)(x+2)=F
Vocaloid:
F means multiply the first term in each bracket
the first term in each bracket is x
so F = first = x * x
Vocaloid:
|dw:1515005830045:dw|
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zarkam21:
okay so like this
F=First x*x
O=Outer 2x
I=Inner -5x
L=Last -5*2
Vocaloid:
yup, just make sure to multiply out the products
so x*x = x^2 and -5 * 2 = -10
Vocaloid:
now, when it says "combine like terms to produce..."
just add the results from F, O, I, and L
zarkam21:
okay now to combine like terms
zarkam21:
so x^2+2x+-5x+-10
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Vocaloid:
good, but also simplify 2x - 5x
zarkam21:
x^2-3x-10
Vocaloid:
awesome, that's the answer for the trinomial part
zarkam21:
perfect now for part II
Vocaloid:
now, for part II, we simply take that 2 from y = 2(x-5)(x+2) and distribute that into x^2-3x-10
so basically just double every term of x^2-3x-10
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zarkam21:
Confused :/
Vocaloid:
|dw:1515006177677:dw|
Vocaloid:
|dw:1515006199274:dw|
zarkam21:
so 2x^2-6x-20
Vocaloid:
perfect
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zarkam21:
that is the answer/
Vocaloid:
yup