Question

how this came ?? please tell
factorise 3x²-x-4​

Answer 1

step 1 Use the sum-product pattern

3x²-x-4

3x² + 3x-4x - 4

step 2 Common factor from the two pairs

3x² + 3x - 4x - 4

3x(x + 1) 4(x + 1) -

step 3 Rewrite in factored form

3x(x + 1) - 4(x + 1)

(3x − 4)(x + 1)

Solution

(3x − 4)(x + 1)

Answer 2

Step-by-step explanation:

-4 should be multiplied with 3 and by adding its factor, it should be -1.

this implies when you add the factors - 4 and 3 you will get -1.

the next step you should check whether x² has any coefficients if it has any coefficient you should divide the coefficient by the factor and multiply x before that.

See x (-4/3 ) , x ( 3/3 )

= (3x-4)(x+1)