Factorise 3x²+5x-12
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hi <3

i'm not sure of which method you will have been taught but i'll try to explain the method i was shown.

so, you need to multiply the coefficient of x^2 by the last value

3 x -12 = -36

now, you need to find two values that multiply to make -36 but add to make 5.

9 and 4 would work. it would have to be positive 9 and negative 4, as these would subtract to give the 5 that you need

now we have:

(x - 4)(x + 9)

however, we need to achieve the 3 from somewhere so it needs to be divided somewhere

9 is divisible by 3 so you can divide it there. as 4 cannot divide by 3, you would move the 3 up to be the coefficient.

thus, your final answer would be:

(3x - 4)(x + 3)

hope this helps :)

it's gonna be 3(X*2 + 4X - 4)

Step-by-step explanation:

Just factor out 3 from the expression