Question

(x^2-4x)^2-30(x^2-4x+2)-4 factorise the given polynomial​

Answer 1

Step-by-step explanation:

Given: polynomial x

2

−4x−21

To find the zeroes of the polynomial

Sol:

The zeroes of the polynomial can be found by equation the polynomial to zero and finding the values of the variable.

Hence, x

2

−4x−21=0

⟹x

2

−7x+3x−21=0

⟹x(x−7)+3(x−7)=0

⟹(x−7)(x+3)=0

Therefore the zeroes of the polynomial are −3,7

Answer 2

Answer:

Completing the square

Put the equation into the form ax 2 + bx = – c.

Make sure that a = 1 (if a ≠ 1, multiply through the equation by. before proceeding).

Using the value of b from this new equation, add. ...

Find the square root of both sides of the equation.

Solve the resulting equation.