Question

A function $f$ is defined by$f\left( x \right) = 2x - 5$ . Write down the values of
$
  \left( i \right)f\left( 0 \right) \\
  \left( {ii} \right)f\left( 7 \right) \\
  \left( {iii} \right)f\left( { - 3} \right) \\
 $

Answer 1

Hint: In this question we simply use putting the values and getting the results.

Now given that,
$f\left( x \right) = 2x - 5$
Now putting the different values of $x$ in $f\left( x \right)$
$
  \left( i \right){\text{ }}f\left( 0 \right) = 2 \times 0 - 5 \\
   = 0 - 5 \\
   = - 5 \\
    \\
  \left( {ii} \right){\text{ }}f\left( 7 \right) = 2 \times 7 - 5 \\
   = 14 - 5 \\
   = 9 \\
    \\
  \left( {iii} \right){\text{ }}f\left( { - 3} \right) = \left( {2 \times - 3} \right) - 5 \\
   = - 6 - 5 \\
   = - 11 \\
 $
Note: These types of questions can be solved by simply putting the different values of $x$ in the given function and thus we will get the different values of $f\left( x \right)$ for different values of $x$ .