Question

6 Factorise 3x² – X-4.​

Answer 1

Answer:

In the given polynomial 3x

2

−x−4,

The first term is 3x

2

and its coefficient is 3.

The middle term is −x and its coefficient is −1.

The last term is a constant term −4.

Multiply the coefficient of the first term by the constant 3×−4=−12.

We now find the factor of −12 whose sum equals the coefficient of the middle term, which is −1 and then factorize the polynomial 3x

2

−x−4 as shown below:

3x

2

−x−4

=3x

2

+3x−4x−4

=3x(x+1)−4(x+1)

=(3x−4)(x+1)

Hence, 3x

2

−x−4=(3x−4)(x+1

Step-by-step explanation:

Hope it's helps you.

Answer 2

Step-by-step explanation:

3x² – X-4= 0

or, 3x² +3x-4x -4=0

or, 3x(x+1)-4(x+1)=0

or, (3x-4)(x-1)=0

or, 3x-4=0. or, x-1=0

or, x=4/3. or,x= 1

Therefore x=4/3 and 1