Question

When I'm solving Quadratic Functions what's another way to solve them without using
x=-b+-SQRTb^2-4ac all over 2a?

Answer 1

factoring them, then using the zero principle

Answer 2

How do i do that?

Answer 3

post up the problem and i'll shew you

Answer 4

there is another methods but this method which you mentioned will be more easy... though if you are interested then send me the problem..

Answer 5

I need part C, I used the other formula for part B.

Answer 6

thanks, give me a sec..

Answer 7

Okay.

Answer 8

your not going to like my answer, because it'll require you to erase some of your work. use the quadratic equation on Part C, and use factoring on Part B

so, you know how to do the quadratic equation, for Part C. So, i'll show you how to Factor for Part B

factoring is FOIL in reverse

we have
4x^2 - 12x + 5

set up my FOIL in reverse, 1 and 5 are the only factors of 5,
( - 1) ( -5)

I need to get a 4x^2, so I will put in factors of 4, which are 2 and 2
(2x-1)(2x-5)

now I FOIL what I made to check if it is correct
(2x-1)(2x-5) = 4x^2 -10x-2x+5
I did it right, so it's factored now.

next, we use the zero principle, its like this:
if a*b = 0, then a=0 or b=0 or both =0

let a = (2x-1)
let b = (2x-5)

solve for x
2x-1 = 0
2x=1
x=1/2

solve for x
2x-5=0
2x=5
x=5/2

so x=1/2 and 5/2


any questions?

Answer 9

x ^{2}+5x +4=0
x ^{2}+(4\times1)x +1=0
x ^{2}+4x +x +4=0
x (x+4)+1( x+4)=0
( x+4)( x+1)=0
x=-4,-1

Answer 10

Just one, I have to use the two different formulas so the FOIL one is for part B what do I use for part C... or is that what the zero principle one is?

Answer 11

@DemolisionWolf

Answer 12

oh, so the FOIL and the Zero Principle are methods that have to be used together to solve for X.

and for the other problme, use the quadratic equation

Answer 13

Ooh, okay. Thank you! :D

Answer 14

^_^