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Mathematics 20 Online
zarkam21:

Help please

zarkam21:

1 attachment
zarkam21:

@Vocaloid

Vocaloid:

Is this a graded test?

zarkam21:

Nope practice

zarkam21:

QC does not permit tests and quizzes, I thought?

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

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

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

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|

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

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

zarkam21:

Confused :/

Vocaloid:

|dw:1515006177677:dw|

Vocaloid:

|dw:1515006199274:dw|

zarkam21:

so 2x^2-6x-20

Vocaloid:

perfect

zarkam21:

that is the answer/

Vocaloid:

yup

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