Math

Applications of Linear Functions

Consider again the equation $5 x + y = 2000$ from the previous pages. You can write such equation in function notation by transforming the equation into its slope-intercept form.

$5 x + y$	=	2000	Equation of the form $A x + B y = C$
$5 x + y - 5 x$	=	$200 - 5 x$	Subtract 5x from both sides.
y	=	$200 - 5 x$	Simplify.
y	=	$- 5 x + 200$	Rearrange the terms.

Thus, the function is denoted as $f (x) = - 5 x + 200.$ This function represents the price per sack of rice if x sacks of rice are sold. For instance, if $x = 10$ (that is, 10 sacks of rice are sold), $f (10) = 1950$ represents the price per sack of rice.

The following figure shows the graph of the function: