Math Homework with (Factrisation) I only know it in french, Its X² + Bx +C ? how do I do it?

Question

I took my notes but they dont seem to make scence. I understand the

_x_=C

_+_=B

Just dont know how to add it in.

My Homework

Ex: X² +5x +4

=(X² +4) + (x + 4)

=X(X+4) + (x +4)

Then the answer is (X+1)(X+4)

How do I get that answer, how do I get the 1 ????

Plz help!

Answer 1

in Ax^2 + Bx + C .... you factor a trinomial into 2 binomials

when you FOIL, you go like this

first * first ...(this gives you A)

outside*outside {the sum of the outside & inside

inside +inside ..{ make up the B value}

Last* last (this gives you C)

x^2 = x*x    (x+)(x-)

factors of "C" are (1,4)(2*2)

which factors of C add to B

+4 * +1 = 4    .......(x +4)(X+1)

Answer 2

X² +5x +4

=(X² +4) + (x + 4)

=X(X+4) + (x +4)

= x (x + 4) + 1 (x + 4)

Take (x + 4) as a common factor,

= (x + 1)(x + 4)

Answer 3

X^2+5X+4=

(X+1)(X+4)

always start with (x     )(x    )    

take the factors of 4: 1,2, and 4(1x4 and 2x2)

and manipulate 2 of the numbers by adding or subtracting them to make them equal the "B" in Bx, which is 5 in this problem. In this case the two numbers are 1 and 4 and put them into the parenthesis

(x    1)(x    4)

now put a + symbol in both parenthesis for this particular problem

(x+1)(x+4)

to prove that this is the correct solution,

multiply x by x= x^2, then x by 4= 4x, then x by 1= 1x, and then 1 by 4= 4.

so then u'll have x^2 + 5x(by adding the 1x and 4x together) + 4

sry if it's confusing

btw x^2 means x squared

Answer 4

ax^2 + bx + c = 0

x = [-b + or - the square root of (b^2 - 4ac)] / 2a

http://www.purplemath.com/modules/quads/...

x^2 + 5x + 4

(x + 1)(x + 4)

Answer 5

x²+5x+4

=(x²+4x)+(x+4)

=x(x+4)+1(x+4)

=(x+4)(x+1)

Hope you can now understand where the (x+1) comes from.

Still in problem? Just inform me.

Have a nice time with your maths homework.