CPM Homework Help : CCA2 Problem 1-19

Jill needs to cut a piece off of a $30$ -foot length of lumber. Create multiple representations ( $x → y$ table, graph, and equation) for the function with $x$ -values that are the length of the piece Jill cuts off and $y$ -values that are the length of the piece that is left over. Which representation best portrays the situation? Why? Explain.

Hint 1:

Make a table.

More Help 1:

What input and output represent the length of the lumber before she cuts it?

Answer 1:

$x$	$0$	$1$	$6$	$20$
$y$	$30$	$29$	$24$	$10$

Hint 2:

Draw a graph. What is the slope?

Answer 2:

First quadrant, decreasing line, passing through the points, (0, comma 30) & (30, comma 0).

More Help 2:

What is the $y$ -intercept? What is the equation?

Answer 3:

$y = 30 − x$

More Help 3:

Decide which representation best shows that when she cuts off a longer piece, the remaining piece is shorter, and explain your reasoning.