Applied exercises: Linear functions

Maple Springs is known for its beautiful Indian summer: In the beginning of fall, the leaves of the trees turn yellow and red and start falling to the ground. Assume that a tree carries 12000 leaves in summer and starts to lose 1000 leaves every week, as fall begins.

(Image source: https://pixnio.com/de/landschaften/herbst/blaetter-im-herbst-gelblich-blaetter-rote-baeume-laub-herbst-herbst-blaetter-baeume)

(a) Set up a function for the number of leaves $f(x)$ on the tree as a function of the number of weeks $x$ that have passed since the beginning of fall.

(b) Draw this relationship in a coordinate system. Plot the number of leaves (in thousands) on the $y$-axis and the number of elapsed weeks on the $x$-axis.

(c) How many leaves are there on the tree after 1, 2, 3, 6 and 12 weeks, respectively?