Question

factor
8x²-16-28x

Answer 1

4(2x² - 7x - 4)

Answer 2

put it in "common" form :)

8x^2 -28x -16 = 0 right?

Answer 3

trop factored the 4, thats good

Answer 4

we can use quad formula to get the roots; then just reverse it back into a factored form :)

Answer 5

we have to use AC method

Answer 6

AC method? air conditioned?

Answer 7

ohhh....the a*c method; thats my method ;)

Answer 8

first right down the setup as tho it CAN factor...like this:

(x...../a)(x...../a) where a = 2 in this case

Answer 9

then we can fill in the signs bythe clues given to us in the equation....think we can do it?

Answer 10

so far:

(x /2) (x /2)

Answer 11

the sign of "C" tells us what to do; the sign of B tells us the sign of the "bigger" number.

if the sign of C is (+); we got 2 options: (+)(+) or (-)(-)...do you know why?

Answer 12

(x+2)
(x-2)

Answer 13

is that an answer? or a response? :)

Answer 14

it is i have no idea what im doing

Answer 15

(x /2) (x /2)

-16 is (-); we need a (+)(-) to fill in;

-28x is (-); the bigger number gets the (-)

(x- /2) (x+ /2)

lets fill in the blanks now

Answer 16

A*c = 2(4) = 8; what does 8 factor into?

1,8 8-1=7 <-- lets use these :)
2,4 4-2=2


(x- 8/2) (x+ 1/2) ; reduce till you cant reduce no more...

8/2 = 4/1...stop!

1/2 = 1/2 ....stop!

(x-4) (x+1/2) if theres still a fraction; put the bottom # in front..

(x-4) (2x+1)

Answer 17

its easier to explain in person really :) and with paper...

Answer 18

very good explanation

Answer 19

9a^2+ 18a+8

Answer 20

step by step please

Answer 21

9 and 8 aint got nothing in common; so we can factor nuthin out to begin with right?

Answer 22

1) set up as tho it CAN be factored...

(a ) (a )

2) we are going to multiply by that first #, that "9"; so we need to divide it back out in the end like this:

(a /9) (a /9)

make sense so far?

Answer 23

yes

Answer 24

3) look at "signs" to fill in our setup; that last # is a +8, it got there by multiplying 2 numbers together; we know that:

(+)(+) = (+) AND (-)(-)=(+) right? so we have 2 options to narrow down


4) that middle #, that +18x; got there by adding or subtracting two numbers together; and we need a (+) result.

we know this:

(+) + (+) =(+) AND (-) + (-) =(-)

So what can we gather from this info?

We need 2 signs that are the same to get a (+) last#; AND those 2 signs have to give us a (+) middle #. lets use (+) (+) for that choice like this:

(a + /9) (a + /9)

We good so far?

Answer 25

5) lets gather a "pool" of options to choose from now; multiply first and last #s together for this:

9(8) = 72....factor this till you get 2 numbers that add to 18

1,72 ; 72+1 = 73...aint it
2,36 ; ....aint gonna be it either :)
4,18 ... getting closer....
8,9 ....hmmm, 8+9 = 17....not quite ther

3, 24 ..... 27 is bad
6,12...looks good :) 6+12 = 18 thats it :)

we will use 6 and 12 in our setup then like this:

(a+ 6/9) (a+ 12/9)

Answer 26

we reduce those fractions till we can reduce no more...

6/9 = 2/3....stop !!

12/9 = 4/3 ....stop!!

(a+ 2/3) (a +4/3) .... whateves got a fraction, but the bottom in front like this:

(3a+2) (3a+4) <-- and we are done