Question

x^2+7x+12
factorise completely
please help me.

Answer 1

(x+4)(x+3)

Answer 2

how. plz show full woking

Answer 3

look at the last term first

Answer 4

what are the multiples of 12? (what multiply together to make 12?)

Answer 5

1,12
3,4
6,2

Answer 6

Do any of those numbers add or subtract from their partner to get you 7, the middle term?

Answer 7

only 3 and 4

Answer 8

since 12 is positive,
and only a negative number times a negative number
-or-
a positive number times a positive number get you a positive,
3 and 4 are either
-3,-4
or
3,4

Answer 9

Now, is 7 positive or negative?

Answer 10

it's positive

Answer 11

so 3 and 4 have to be positive too. if they were negative, it would be a negative 7

Answer 12

So far wh have ( 3)( 4)

Answer 13

Now the last step. the first term is x^2.

Answer 14

the coefficaint is 1, so your terms will be x and x. (x*x=x^2)

Answer 15

well, in my point of view, it is just easier to rewrite x^2+7x+12 as
x^2+4x+3x+12
Now x^2+4x+3x+12=x(x+4)+3(x+4)
distributive property (x+4)(x+3)

Answer 16

so finally you have (x+4)(x+3)

Answer 17

p.s. once you do this a few more times, it will get a lot easier; I just wrote everything out so you wouldn't be confused by a step.

Answer 18

x^2+7x+12
=x^2+4x+3x+12
=x(x+4)+3(x+4)
=(x+4)(x+3)