Question

How would I factor 5x^2 - 8x +3?

Answer 1

I'm doing the mistake method (that's the way I prefer) and so far can't get the answer

Answer 2

So far I've gotten (5x- _) (5x-_) but don't know how to do it since 3 and 5 as opposite signs don't equal eight

Answer 3

Can you show me the work you have so far? So i can identify where you made the mistake?

Answer 4

Ya lemme write it out for you, one sec

Answer 5

\[(5x^2 - 8x +3)\]
Using the mistake method I brought down the negative sign and the 5x's so it looks like this now:
\[(5x -[number]) (5x+[number])\]
I did that because positive 5 and 3 make a positive so the second parentheses has a positive sign in it
And so then you're supposed to multiply 3 and 5 right?

Answer 6

which gets you 15

Answer 7

and the factors of that have to somehow equal -8 but i don't know how to get -8 in this scenario

Answer 8

I'm not very familiar with this method...are you allowed to use a different method?

Answer 9

ya you can show me that one if you want

Answer 10

like the method you're familiar with

Answer 11

Ok
\[\huge~\rm~ax^2+bx+c=0\]
\[\huge~\rm~5x^2 - 8x +3 \]
a=5,b=-8,c=3

Answer 12

for the top you get 15 bottom remains -8
Next we solve by grouping
(5x^2+15)(5x^2-8)
can you break those down?

Answer 13

umm

Answer 14

i think?

Answer 15

is it (x + 3)(5x^2 - 8)?

Answer 16

hello haha

Answer 17

Wait lets take a step back..

Answer 18

(5x-3)(x-1)
is what i got
The factors the sum to -8 are -5 and they multiply to make 15

Answer 19

ohhh ok

Answer 20

Do you understand?