Question

Given f(x) = 2 / x-3 , find f(4)

Answer 1

Option #1:

$f(x)=\frac{2}{x-3}$

f(4), this means that x = 4

To find f(4), substitute/plug in 4 into "x" in the function:

$f(x)=\frac{2}{x-3}$      Plug in 4 into "x" since x = 4

$f(4)=\frac{2}{4-3}$

$f(4)=\frac{2}{1}$

f(4) = 2

Option #2:

$f(x)=\frac{2}{x} -3$

f(4), this means that x = 4

To find f(4), substitute/plug in 4 into "x" in the function:

$f(x)=\frac{2}{x} -3$

$f(4)=\frac{2}{4} -3$    To combine fractions, they need to have the same denominator. Multiply -3 by $(\frac{4}{4} )$ so that they have the same denominator.

$f(4)=\frac{2}{4} -3(\frac{4}{4} )$

$f(4)=\frac{2}{4} -\frac{12}{4}$      Combine the fractions

$f(4)=\frac{-10}{4}$      Simplify the fraction

$f(4)=-\frac{5}{2}$