Question

factor
2x^2 – 5x – 12?

Answer 1

(2x +3 )(x -4 )

Answer 2

do u need any explanation?

Answer 3

1) Find roots of 2x^2 – 5x – 12 = 0
2) Answer is: 2(x-1st root)(x-2nd root)

Answer 4

Yeah an explanation would be good.

Answer 5

well the 2x and x in the brackets are easy - this gives the 2x^2
now we need to get 2 numbers which will give you the middle value -5x
- the two numbers must also give -12 when multiplied together and 1 of these 2 numbers must also multiply 2 to give the -5.
its now trial and error :- 3 x -4 gives -12 and we can get -5 if we multiply the -4 by the 2 (from the 2x^2).
-4 x 2 + 3 = 15
its a good idea to put them into columns as below
2x^2 -12 -5x
-----------------------------
2 x 1 4 x -3 2x 4 - 3 = 5 - no
2 x 1 -4x3 2 x-4 + 3 = -5 yes

Answer 6

thats a bit long winded i know - but practice theses a lot and it will come to you quite easily

Answer 7

error in the above i meant to write
-4 x 2 - 3 = -5