Question

factorise x²-21x-196​

Answer 1

In context to data given in the question,

We have to determine the factors of the given equation.

From the question,

We have,

Expression - $x^2-21x-196$

As the above expression is in form of $ax^2+bx+c$

So, for finding the value of expression,

We will multiply "a" and "c" and split the product ac in such way that after adding/subtracting the number we get the value of b.

So, Solving the expression,

$x^2-21x-196=0\\=>x^2-28x+7x-196=0\\=>x(x-28) +7(x-28)=0\\=>(x+7)(x-28)=0\\=>x = -7, x = 28$

Hence, the value or factors of the expression will be -7, 28.

Answer 2

• As per the data given in the question, we have to find the value of the expression.

        Given data:- $x^{2} -21x-196.$

        To find:- Value of the expression.

        Solution:-

• We know that factorization means reducing any algebraic or quadratic equation.

• steps to solve quadratic equations,

• Step 1: Rearrange the given quadratic so that is it equal to zero.

• Step 2: Factorise the quadratic.

• Step 3: Form two linear equations.

• Step 4: Solve the equations to find the roots of the equation.

        Therefore,

          $\begin{array}{l}x^{2}-21 x-196=0 \\=>x^{2}-28 x+7 x-196=0 \\=>x(x-28)+7(x-28)=0 \\=>(x+7)(x-28)=0 \\=>x=-7, x=28\end{array}$

      Hence we will get the value $-7$ and $28.$