Question

# If $\;p(x) = {x^2} - 5x - 6$; find the value of $p(3)$.

Hint: Replace the value of $x$ with 3.

We have the given equation as
$\;p(x) = {x^2} - 5x - 6$
Putting the value of $x = 3$ on both LHS as well as RHS, we get
$\Rightarrow p(3) = {3^2} - 5 \times 3 - 6$
On further solving, we get
$\Rightarrow p(3) = 9 - 15 - 6$
$\Rightarrow p(3) = - 12$
So, this is the required solution.

Note: In solving these types of questions, simply put the given values of the variable and calculate the required values to obtain the solution.