Question

Factorize the following

$x^2+14x-15$

• A. $(x-1)(x+15)$
• B. $(x+1)(x+15)$
• C. $(x-1)(x-15)$
• D. None of these

Answer 1

The correct option is A $(x-1)(x+15)$

In the given polynomial $x^2+14x-15$,

The first term is $x^2$ and its coefficient is $1$.

The middle term is $14x$ and its coefficient is $14$.

The last term is a constant term $-15$.

Multiply the coefficient of the first term by the constant $1\times (-15)=-15$.

We now find the factor of $-15$ whose sum equals the coefficient of the middle term, which is $14$ and then factorize the polynomial $x^2+14x-15$ as shown below:

$x^2+14x-15$

$=x^2+15x-x-15$

$=x(x+15)-1(x+15)$

$=(x-1)(x+15)$

Hence, $x^2+14x-15=(x-1)(x+15)$.