Question

factor 21x^2-49x-9x-21

Answer 1

idk how i got 7x(3x-7) 3(3x-7) and i know its wrong

Answer 2

is the original problem
21x^2-58x-21 ?

Answer 3

no

Answer 4

right,so thats 21x^2-40x-21=0
right ?

Answer 5

yeah and then the product of 21 and -21 is -441 and then 40 so the two numbers are -49 and 9

Answer 6

that is correct,
see above u have written -49x - 9x
instead of what u got now as
-49x+9x

Answer 7

oooh i see wow

Answer 8

now whats common from first 2 terms in
21x^2-49x-9x-21 =0?

Answer 9

7x

Answer 10

i got the answer :P -3/7 and 7/3

Answer 11

yup, correct.

Answer 12

im having problems with another equation

Answer 13

which ?

Answer 14

i got to the point 9 + or - sqrt of 1 all over 4

Answer 15

9 from where ?

Answer 16

Compare your quadratic equation with \(ax^2+bx+c=0\)
find a,b,c
then the two rots of x are:
\(\huge{x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}}\)

Answer 17

yeah b is 9

Answer 18

nopes, b is -4

Answer 19

oh wait nooo i gave you the wrong equation! no wonder

Answer 20

lol :P

Answer 21

still b is -9

Answer 22

but in that equation it says -b so -(-9) is 9

Answer 23

inside i did put put -9^2 = 81

Answer 24

yes, u are correct
\(\huge\frac{9 \pm \sqrt{1}}{4}=\frac{10}{4},\frac{8}{4}\)

Answer 25

wait you are just adding and subtracting the 1?

Answer 26

obviously lol never mind i feel stupid

Answer 27

got it now ?

Answer 28

yes, it was a stupid moment :P

Answer 29

ok i did another one and i got 4+-sqrt of 28 all over 2 @hartnn

Answer 30

question ?

Answer 31

its the first one that sent you

Answer 32

thats correct :)

Answer 33

but how do i factor it?

Answer 34

do u want to factor or do u want to use quadratic formula?
anyways its not factorable....

Answer 35

so what would be the answer?

Answer 36

i cant simplify it?

Answer 37

all u can do is
\(2 \pm \sqrt7\)

Answer 38

\(\sqrt{28}=2\sqrt7\)

Answer 39

how does that equal to that

Answer 40

\(\sqrt{28}=\sqrt{7*4}=\sqrt{7}\sqrt{4}=2\sqrt{7}\)

Answer 41

got it

Answer 42

you are the best!

Answer 43

lol. glad to hear that :)
u too are awesome ;)

Answer 44

lol thank you, well i gotta keep doing this stupid hw

Answer 45

best of luck for that.