How the hell do you factor things like

how the hell do you factor things like

7a^2 + 53a + 28

Can't do it by grouping can you?

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ebin trole thread XD

>being thing much of a brainlet
You just think about it. I did it in my head.
(7x+4)(x+7)

Now get off Veeky Forums, you're underage

yeah, feed the shitty thread, actually spoonfeed the guy, and ONLY then tell him to fuck off
you're fucking retarded

>I did it in my head.
you did it wrong in your head

Nope, just an old man learning again you autist

you can
7a^2+49a+4a+28
7a(a+7)+4(a+7)
(7a+4)(a+7)

i see now. Does the quadratic formula do this as well, or is it different with coefficients?

the quadratic formula first completes the square and then expresses the roots as deviations from the roots of that square

see en.wikipedia.org/wiki/Quadratic_formula#Derivation_of_the_formula

I'm not understanding what you're asking. You can use the quadratic formula to factor it.
if ax^2+bx+c is your expression and r_1, r_2 are the two roots given by the quadratic formula then I think it can be factored as a*(x-r1)(x-r2)

You can use the quadratic, you'll get the same answers.

When the coefficient of x^2 isn't 1, it's still pretty easy.

2,4,7,12 are the factors of 28, so it's going to be a combination of those
The 7 is going to be on an x term.

From there you do arithmetic and see that 49+4 = 53

That means it's 7x+4 and x+7

7a^2 + 53a + 28
28 * 7 = 196
(7a + )(7a + )
7^2 + 2^2 = 53
7^2 * 2^2 = 196
(7a + 49)(7a + 4)
(a + 7)(7a + 4)

>it's a "mathematical intuition" problem

>(7a + 49) becomes (a+7)
Wat

(7a + 49) = 0
a = -49/7 = -7

(a + 7) = 0
a = -7

dude wtf that pic just broke math

Looks nice, huh?
From line 4 to line 5 you divide by (a-b)
a-b=0 since a=b and you can't divide by zero.
This is a showcase mathematical fallacy.

>2b = b
>2 = 1
>solved by dividing by b

>2b = b

Anyone find factorising polynomials really soothing?
I don't normally like algebra that much but there's something really nice about factorising.

>a+b = b

0 + 0 = 0. What's wrong, summer kid?
>inb4 "i was pretending to be retarded xdd"

>2b = b
>b = 1

Are you seriously trying to tell me that you don't know of a number that when multiplied by 2 is equal to itself?

(hint it's 0. yes, you can divide by 0)

Oh yeah y'know, simple algebra.

Where you divide by 0.