Question

Using special products, simplify :

$(x-15)(x+11)$

Answer 1

Step 1: Identification of identity

We need to identify the identity first,

Here, the question is in the form of $(x+a)(x+b)$ which is equal to $x^2+(a+b)x+ab$

So if we compare the question with the identity we get $a=-15,b=11$

Step 2 : Applying the formula

$$\begin{gathered} (x-15)(x+11)=x^2+(-15+11)x+(-15\times 11) \\ =x^2-4x-165 \end{gathered}$$

Hence, the product is $x^2-4x-165$.