Question

Factor this http://screencast.com/t/7oezPour5cV

Answer 1

you dont knw how to factor

Answer 2

2x^2+x-3 factored would be (2x+3)(x-1)

Answer 3

you have the answer there. @Christos something u dont understand in how to factor that ?

Answer 4

@ganeshie8 certainly I don't understand how I should start? Will you guys be willing to show me the first step? Thee are certain expressions that just dont ring a bell on me, it's not that I cant factor, just some specific ones

Answer 5

i understand, let me guide u factor this

Answer 6

ty man

Answer 7

\(2x^2 + x - 3 \)

Answer 8

compare it wid

\(ax^2 + bx + c\)

Answer 9

ok

Answer 10

we need to pick two numbers whose product equals \(ac\), and sum equals \(b\)

Answer 11

a=2
b=1
c=-3

Answer 12

can you pick two numbers whose product equals -6, and sum equals 1 ?

Answer 13

\[2x ^{2}+x-3=2x ^{2}+3x-2x-3\] (2*-3=-6,3-2=1)
\[=x \left( 2x+3 \right)-1\left( 2x+3 \right)=\left( 2x+3 \right)\left( x-1 \right)\]

Answer 14

I dont think I can :(

Answer 15

tell me what are the factors of -6

Answer 16

-1 -2 -3

Answer 17

and 1, 2, 3 also

Answer 18

ooh ok

Answer 19

so, 3 * -2 = -6

Answer 20

3 + -2 = 1

Answer 21

3 and -2 are our numbers !

Answer 22

So we dont take into considaration b ? We just add and multiply a and c?

Answer 23

\(2x^2 + x - 3\)

you need to rewrite x as 3x-2x

Answer 24

we did consider b, the numbers we pick must multiply to ac, and addup to b

Answer 25

"3 * -2 = -6"
"3 + -2 = 1"

Where is b ?

Answer 26

we picked 3 and -2, cuz they multiply to ac, and addup to b

Answer 27

look at the given expression, b = 1

Answer 28

hm the second expression ye

Answer 29

\(2x^2 + x - 3\)

can be written as :

\(2x^2 + 1x - 3\)

Answer 30

compare it wid ax^2 + bx + c, and tell me whats b ?

Answer 31

yea I know it's 1, I just dont know what do it with it :D

Answer 32

lol

Answer 33

so when you're asking where is b, you knw now that its there, and it is 1 :)

Answer 34

from my understanding

we take a*c = whatever it gives
then a+c = whatever it gives

Answer 35

not exactly

Answer 36

hm

Answer 37

we take a*c, tell whats a*c, in our current example ?

Answer 38

its -6

Answer 39

so we take that -6, and find its factors. that addup to b

Answer 40

-6 = 3*-2

Answer 41

when you say "add up" what do you mean exactly?

Answer 42

when u add both the numbers, you must get b

Answer 43

we picked 3 and -2, add them and see if u get b or not

Answer 44

if p, q are the two numbers, you should pick them in a way such that :-

pq = ac
p+q = b

Answer 45

thats all

Answer 46

I see now

Answer 47

great :) you do few more problems u wil see more clearly

Answer 48

Ok so, we have a*c = -6

a-b = 1

but how do I proceed with this information in hand?

Answer 49

heres the full solution, go through

\(2x^2 + x - 3\)

\(2x^2 + 3x - 2x - 3\)

\(x(2x + 3) - 1(2x + 3)\)

\((2x + 3)(x - 1)\)

Answer 50

a-c ***

Answer 51

no

Answer 52

/facepalm I am such a dummy some times, I can see it clearly now, thanks again

Answer 53

its,

pq = ac
p+q = b

Answer 54

cool all geniuses have few dummy corners ;p

Answer 55

yea yea I see, I get you now

Answer 56

hihi xP

Answer 57

good :)

Answer 58

ty dude